The Ché Café Collective, a student-run co-op on campus here , in the woods past Revelle Plaza. As Fran Berman puts it, it's a touch of the 60's at UCSD. It has an interesting atmosphere.
The collective has three primary functions: a venue for indie bands, a meeting place for some campus organizations, and as a kitchen. Unfortunately, the kitchen has been closed to the public since October 2005, when Ché voluntarily stopped serving food to give themselves time to resolve financial problems and cleanliness issues (i.e. rats). They plan to return when those issues are resolved.
The rest of this information is for historical reference only.
All-you-can eat meals are on Thursdays from 17:30 to 19:00. A plate costs $3; for $4-5 you get all you can eat! One of the best deals anywhere. You even get a discount if you bring your own plate/utensils. Watch for posters on campus (and email) describing their hours (if they have any...), and the menus for the evening meals.
They make a mean garden tempeh sandwich. Mean in a good way, not mean in the sense that it has hair and fangs. It has no hair, no fangs. In fact, it has no animal parts whatsoever.