The original Connie's pizza is down on the south side in Bridgeport by Archer and Halsted. FANTASTIC pie. My favorite.
Lou Malnotti's (sp?) has a few restaurants here and there. Good pizza, a little too much sauce for my tastes, but you can always scrape some extra off.
A lot of times, the local hole in the wall pizza joint makes the best pie. Trial and error is the only way to sort them out, unfortunately.
Good Luck!