Note: As the last-updated date suggests, this writeup is super outdated! I haven't had time to update it. Many of the places mentioned are still around though, so you might be able to gleam some utility from it.
This is a question that invariably gets asked by freshmen and visitors to SMU alike, and after a year of buzzing around campus, I've had the opportunity to visit many of the F&B establishments around that area. This list is not meant to be exhaustive, as I'm well-aware that there're probably exotic or obscure places that I have yet to visit. However, it will be continously updated as I continue to discover and visit new places to eat and drink at.
One thing for certain about finding nourishment near and around campus is that one has to be prepared to pay the city-area premium, prices are generally slightly higher across the board. Other than a few rare exceptions, you won't find meals with heartland hawker <=$2.50 type of prices (feel free to drop me a mail if you know of any!).
I try to list all the places I know of here, as opposed to only those I like, and let you make the decision as to whether they're worth going to.
These places form the backbone of my meal choices during term time - the first resort - if you will. If you're around campus often, consider the following places to avoid breaking the bank.
Isle Eating House @ Parklane, 2F - Situated along Selegie Road and accessible via PoMo, Isle Eating House is one of my personal favourites. While they offer a selection of zhi char dishes and decent western food, the mixed rice is by far the most value-for-money choice there, and is unsurprisingly also the choice of most of their customers. 2 vegetables and 1 meat will set you back $3.20. A cold drink (tea/coffee) is a further $1.30, bringing the total bill to $4.50.
Kopitiam @ Manulife Centre, 1F - Directly opposite the road from SIS, Kopitiam is perhaps one of the first food courts that visitors notice when they come to SMU. Food is mostly mediocre there, but it's convenient (nearby) and thus good for when you're in a hurry. Some of the better stalls are the Thai stall (green curry, fried rice) and the ramen stall (pork and chicken ramen are both good). The mixed rice stall is also passable depending on the ingredients you pick. Freshmen will want to apply for a stored-value Kopitiam 'Institution' Silver Card, which will impart a 20% student discount on any food and drink purchase at the Manulife Center outlet only. Cards are available at the dim sum stall, where filling out of some simple details on a clipboard is required.
Koufu @ SMU Concourse, B1 - The closest thing SMU has to a cafeteria. It's right smack in the middle of the basement concourse, underneath the Library, though the food is not really good. Amongst the mixed rice places around campus, the Koufu one is the one I visit the least. Again, the Thai stall does a little better than the rest (they have pretty much the same stuff on their menu as the Kopitiam Thai stall, try the green curry or the fried rice). Another stall of note is the Western stall, try the fish and chips for large servings, or the chicken chop spaghetthi if you're looking for a non-fried flavourful meal. Queues form quickly though, so go early. SMU students are supposed to get discounts at Koufu when they flash their matriculation card at the cashier, the discount amounts are pretty arbitrary however, you may get anything from 15 cents to 50 cents off.
Subway @ SMU SIS, 1F - Across the road from Kopitiam, Subway is a pretty self-explanatory option. They don't show it anywhere, but the $5.00 deal (6-inch sub, 16oz drink) is available nevertheless. They run a loyalty programme through the use of Perx, a mobile application that you can download. Any 6-inch sub entitles one to a 'chop', a footlong gives two 'chops', and nine (9) chops gives you a free $5.00 deal. The branch is tiny, so no indoor seating, visit the PoMo branch if you must have air-conditioning.
Subway @ PoMo, B1 - Exactly the same as the SMU branch, except at PoMo which is along Selegie Road. In fact, both outlets are owned by the same franchisee and it is not uncommon to see a guy run over from the SMU branch to the PoMo one to get surplus bread towards closing time, so as to not have to bake up a new batch.
MOS Burger @ PoMo, 1F - If you're sick of Burger King, MOS Burger is waiting for you!
Waterloo Centre coffeeshop - Tucked a little way down Waterloo Street is a pretty comprehensive coffeeshop with a directly translated name "Food Summons". The mixed rice stall has a very decent spread with very economical prices ($2.70 for 2 vegetables and 1 meat) and the drinks are reasonable ($1.20 for iced milk tea). The stall of note however, is the char kway teow one occupying half a lot a little way in. The base $3.00 serving is more than enough quantity-wise for me, and the cockles they use are fresh. They also sell other favourites such as fried hokkien mee, which can be gotten at $3.50 onwards. Honorable mention goes to the chicken rice stall (Leong Yeow), which sometimes makes an appearance during school camps as a convenient source of takeaway food. There is also a western stall that more or less clones an Astons Express outlet (down to the font and branding!) called "Steak Hut" that you might want to try, though it can get pricey and only the cheapest of the sets there actually meet the <$7.00 limit of this category. All in all, this coffeeshop is definitely one worth visiting if you're looking for a little more variety and don't fancy taking too long of a walk.
Kopitiam @ Plaza Singapura, 6F - If you have time and are willing to make the 10-15 minute walk to Plaza Singapura, the Kopitiam there has a far wider range of options than the Manulife branch. Do note that the student Kopitiam card only imparts a 10% discount at the Plaza Singapura branch.
Burger King @ NTUC Income Prinsep House, 1F - A fairly new branch, has pretty cosy dimensions but can get crowded during peak periods. The usual $3.95 deals (buger, fries, drink) are available, great for that fast food craving.
Tea Party @ SMU SOE/SOSS, 1F - This black-painted unmarked stall (I hear they now have a small signboard) on the first floor of the SOE/SOSS building can be recognised by the hollering of order numbers by the lady inside to let customers know that their order is ready. Their business is in pasta, cooked in a number of ways. The $4.50 (it is now $4.80, damn 'inflation') set gets you a box of spaghetthi/linguine, and a cup of iced lemon tea. It really isn't that good though. The box contains little in the way of ingredients, you're essentially getting hastily boiled pasta topped off with an unremarkably salty sauce mix. The few times I've eaten there have left me unsatisfied. For $4.80, you could get a much more satisfying meal elsewhere. Not to worry though, if the food doesn't turn you off soon enough, the ridiculous queue during lunch time will.
New Malay Stall @ SMU SOE/SOSS, 1F - Officially called "My Toast Global", their signboard is conveniently facing a wall, so I just refer to it as the "new malay stall". Directly across the floor from Tea Party and right next to Mr. Bean, it serves Malay cuisine (mee siam, mee rebus, nasi lemak, etc). You may want to give it a go.
Al-Jilani Restaurant @ BIG Hotel, 1F - Located along Bencoolen Street and opposite Sunshine Plaza, this is one of the few 24-hour eating places around campus. As the name suggests, all manner of Indian and Malay cuisine is available here. Good for supper during camps and the (hopefully) rare occasions that you may need to stay overnight in school.
CHIPPY British Takeaway @ Raffles City Plaza Singapura, B1 - I have just been informed that the Raffles City branch has closed down, but not to worry, there's one at Plaza Singapura! CHIPPY is a great place to satisfy that fried food craving. It's unhealthy, but most comfort foods are anyway. As the name suggests, it is takeaway only, so you'll have to find seating elsewhere.
3838 Eating Place @ 52 Queen St - I have walked past this coffeeshop before, and according to a recommendation I've received, the Roasted Delights stall is good and most importantly has a meal for $2.50. It is now on my list of places to check out personally. If you're a fan of roast meat (char siew), you might want to give it a shot too. It is essentially on the other side of Waterloo Centre, and you might be able to walk through if you're already on Waterloo Street (though I have not tried).
Sunshine Plaza @ 10 Prinsep Link - A straight walk down on the side of the boarded-up Bencoolen Street, Sunshine Plaza has a number of food options to choose from. The wanton mee is not bad but a little pricey. There's also Victor's Kitchen if you need to satisfy a dim sum craving. Some have also recommended to me the Thai food there, though I have not tried it before.
Fortune Centre @ 190 Middle Rd - Diagonally opposite Sunshine Plaza and a good 10-15 min walk away depending on where in campus you are, this building is full of eating places serving vegetarian food. If this is your thing (or you're a vegetarian), you'll probably want to come here.
These are the pricier food options that you might want to save for occasions or get-togethers.
Standing Sushi Bar @ 8 Queen St - Occupying a lot on the side of Singapore Art Museum, SSB is known for their $3 salmon sashimi during Monday and Thursday nights. Unfortunately, this draws a ridiculous queue long before the doors open, so I have yet to actually get my feet through the door to try it T_T. Do note that they have set timings for lunch and dinner, so do check beforehand and show up early to avoid having to contend with the queue.
Pepper Lunch Express @ Plaza Singapura, Kopitiam, 6F - The hot plate (teppan) quick service outlet from Japan is here! Shrunk to fit a food court stall within Plaza Singapura's Kopitiam, their signature Beef Pepper Rice and Curry Rice are all available.
Astons Specialities @ The Cathay, 4F - Western cuisine. Nice spacious outlet with decent food. If you're feeling ravenous, the $14.90 ieat Superburger is very satisfying (think Carl's Jr. size).
Chef's Kitchen @ 261 Waterloo Street - Pretty run-of-the-mill zichar place, serves up decent food and is a nice place to go to for large groups.
Fatboy's The Burger Bar @ MacDonald House, 1F - Large, specialty burgers. Lots of variety and ordering options.
Din Tai Fung @ Manulife Centre, 1F - New tenant, the lot used to be occupied by a RamenPlay.
Tim Ho Wan @ Plaza Singapura, 1F - If you manage to get to the front of the queue, good for you!
Popeyes Louisiana Kitchen @ The Cathay, B1 - It's fried chicken, nuff' ced. The Cajun Rice Platter is one of my favourites, although you'll want to add a side or a drink to complete it.
Pastamania @ SMU Concourse, B1 - Perpetually underpatronised, this is a convenient choice if you're in need of a quiet (halal) restaurant that serves passable pastas and soups.
Maki-san @ The Cathay, B1 - Bespoke makizushi and salads made-to-order here. It's a little pricey but the concept is interesting.
Saizeriya @ The Cathay, B1 - Budget Italian cuisine.
Kith Cafe @ Park Mall, 1F - A nice full-service cafe, tucked away at a quiet corner of Park Mall's first floor and across Dhoby Ghaut Green. Prices are steep, but the quality is there. Good for getting away from the hustle once in a while. Both indoor and outdoor seating is available.
Mr. Bean @ SMU SOE/SOSS, 1F - Next to the new Malay stall is the long time tenant Mr. Bean. Get your fill of soya bean products here. They also carry snacks like hotdog buns, as well as their signature pancakes.
KOI Cafe @ Plaza Singapura, 1F - Bubble tea, juices, coffee. Personally, I go there for the macchiatos. Do note this is a proper outlet with some indoor seating (if you're lucky enough)
Kopitiam @ Manulife Centre, 1F - The drinks here are expensive, $1.80 (!!) for iced tea/coffee with milk. If you use the student card it's a little more bearable at $1.44, but still pretty darn expensive compared to other places. The upside though is that the queue is usually manageable, and if you're in a hurry you can't be a choosy. I find the coffee/tea to be much too thick for my tastes, so I always get them to dilute it, but YMMV. Their dim sum stall has the usual stuff, baos and all, nothing great, but convenient nevertheless.
Koufu @ SMU Concourse, B1 - With the student discount, the drinks are actually pretty cheap ($1.05 for iced tea/coffee with milk, $1.20 undiscounted)! Forget about getting one during peak hours though, you'll need a good 15-20 minutes to get to the front of the queue. Like Kopitiam, they too have a dim sum stall which is useful for grabbing a quick bite.
Loaves Me @ SMU Concourse T-Junction, B1 - Relatively new tenant, queues are usually short. The coffee there is way better than the Kopitiam/Koufu fare, but the price is subjected to a premium. They also sell a variety of snacks and (quiet!) indoor seating is available.
Rochor Original Beancurd @ Selegie Road - This is the original Selegie beancurd that people talk about. A cup of cold soya bean milk and a fried dough stick are a personal favourite of mine. Air-conditioned seating is available on 2F.
Momolato @ SOE/SOSS, 1F - Artisan ice-cream/gelato can be gotten from this small corner shop near the entrance of the SOE/SOSS building. They're a little pricey compared to some other places, but their ice cream is decent.