I prefer the cafes on the southside of Berkeley, but if I'm stuck on Northside, I love going to Brewed Awakening. There isn't that much to eat, but the coffee's good and there's usually seating available. There's plenty of outlets so you can plug in your laptop. The only down side is that it closes around 10 unlike the southside cafes which are opened til like 12 or 1. Great place to meet up with someone to chat, but not really a place for late night studying.