Lots and lots of cheap books in English, French, German and other languages, hosts debates and book clubs and live music evenings, has the friendliest owner ever and is, in general, the kind of a lively and lovely book store I want to own or work in some day. The first time I visited, I walked out with about fifteen paperbacks in my bag.
The largest UniCafe cafeteria has the most varied range of dishes available on any given day, usually one or two vegetarian/vegan options, a chicken dish and a red meat dish. There's a lot of space but of course, due to the location and lunch list it's crowded during the students' lunch hours (11am-1pm), and around 4pm.
Student-friendly prices, tasty lunch menu, pretty awesome sandwiches and cakes/pies. In addition, there's a book store in the same space and a library right above! How much better can it get?
The place is fairly small but in a good location, does take-away and reservations (though you can just walk in), has a pretty big menu and fast service. The prices have gone up in the recent years so I can't say anything about the current quality of food, but Daruma is where I ate sushi for the first time so I'll always think fondly of it.
Student-friendly prices despite the central location, reasonable opening hours, friendly staff and the cheapest coatroom fee in Helsinki. Several pool tables are available downstairs if you're so inclined, and they mostly play classic/hard rock but not so loud you can't talk with your friends.
Thai Orchid Itis is situated in the Itis shopping mall, formerly known as Itäkeskus. It has a gorgeous variable buffet (sushi included) available every day from noon-ish till late afternoon. Pricey on the weekend in comparison to others but well worth it.
Another student bar with cheap Wednesdays and more of a club house music list. A comfy place, though, and often hosts freshman week events. Apparently the Sunday brunch is popular, too.
It's a pub where the beer is so cheap the only reason they're in business is because people come to get a good buzz going before continuing somewhere else. Friendly staff and clean toilets, but I wouldn't recommend spending your entire evening here.