I moved away almost a year ago, but here is what the deal was a year ago. Most of it has been covered already.
The Break is a good action room.
Riverbend in Alton, 15 minutes North of Granite City has a 9 ball tournament on Sunday at 3:15 and action can be found there as well.
Cue and Cushion is a nice clean room, probably not as much action there but a nice place to play and by far the largest selection of new and used cues in St Louis.
I'm haven't been to Doug Patrick's place but I hear it is nice.