The back of the football tickets was always nice -- buy one get one free burrito supreme at the Bell (I think that's what it was anyway). Late night Bell runs (following basketball at the rec) were a common occurrence for me as a student.
Good cheap options: Kreem kup, Q card thingie, BK for a buck, weekly special at Subway, the dozens of 10cent wing places, and best of all, free Sonic Burgers because some guy I knew had a stack of free Sonic Burger coupons taller than me (I think this guy is now in prison).
Bad cheap options: Anything at Rusty's.
SD, what was your favorite iteration where you bartended? I once had a buffalo burger there, but I can't remember what the place was called then.