Café du Midi

This café isn't one of the cheaper ones but it has the best fondue I have ever eaten (so far ;)). The atmosphere is very cosy and homey.
Unfortunately, the waiter/waitresses mostly only speak French so take your dictionaries with you ;) (those who don't speak French).
My favorite fondue was "fondue moite-moite" with baguette and potatoes. Very yummy. The portions are really big but if you must eat an appetizer I'd eat a small salad to have a balance to all the cheese.

Never drink a "cafe glace" (iced coffee) there, it's way too expensive for what they offer and there are lots of small cafes in Fribourg where is tastes way better :).