You have to try the Skylark on Halstead at Cermak. About 10 taps with Bells and Three Floyds in the mix. Great Food. It looks like a dive, but it ain't.
Kasey's Tavern on South Dearborn is a good spot to hit as well.
skylark is a great place to drink decent beer with no television to distract from good conversation.
i also have to say that maproom and hopleaf have an amazing selection. revolution brewing and piece are excellent brewpubs as well.
I go to Clark St. Ale House (Clark & Chicago) quite often. I work right by there so it's an easy go to. They always have a great selection. Long Room is great. Great beers and chill atmosphere. New place that just opened Blokes & Birds has a decent selection as well. Real cozy in there.
Just north of the city in Evanston there are a few good places as well. There is a wonderful pizza place called Union Pizzeria that has great pizza and a decent beer selection.
personally being the mick that i am and being stranded in orland park im a big fan of sam mcguires right by the mall but not on saturdays. only because im not a big fan of huge crowds. other than that Mrs. Obriens isnt to bad either