Pete's is one of those places where you meet the friends that you never knew that you had. The pianists, or comedians, or MCs, or whatever you want to call them, are so funny and irreverent that it's like sitting around in someone's living room having a giant, rolling laugh.
If you don't like huge crowds, this isn't the place for you. You have to either come early or be very aggressive to get a seat at one of the tables, otherwise it'll turn into a couple of hours standing around the edges of the room or at the bar. Also, if you're easily offended don't even bother, you'll be mad in the first five minutes. The comedians have filthy, filthy minds and mouths.
But if you're into meeting people, laughing like mad, and don't mind squirming your way to the bar like you're trying to escape from the sardine can, you'll be right at home.