Are you looking for labelled/branded glasses or just plain barware?
You can find some basic pint/pilsner/weizen glasses at Target. Restaurant supply stores (there are a few on Madison, just west of the loop) will have some similar plus mugs, goblets and other heavy glass styles
If you are looking for Belgian glassware (snifters and the like) I have had the best luck on eBay. I have a fairly large collection of beer glasses for all styles and most came from eBay, though they are all branded (Delirium, Unibroue, Duvel, etc).
One recommendation I can make is to find some of the
Sam Adam's Perfect Pint Glass. I use one of these 80% of the time. It does just feel right in the hand, and is not too thick of glass. You can usually get them on eBay quite a bit cheaper.
Jamie