I would definitely suggest going to Harry's Chocolate Shop. It was named Best College Bar in America by Rolling Stone magazine a few years back. It's pretty cool, but expect to wait in line. And buy a Harry's shirt, too. They are really cool and you will see people wearing them all over campus.
There are a few other bars on/near campus. Jake's, The Neon Cactus, and Where Else? are all pretty popular, too.
As far as restaurants.... if you like Greek food, you have to eat at The Parthenon on Chauncey Hill. (Also on campus.)
There are also lots of restaurants in Lafayette, too. Tons of chains.
Why are you coming to my campus??