There's also a St. Louis social group here on AZB, which is mostly dead, cuz I think everyone forgot about it. :/
http://forums.azbilliards.com/group.php?groupid=29
Here's a St. Louis Area Pool group on FB:
http://www.facebook.com/groups/312983062158417/
Here's another one, Billiards-STL:
http://www.facebook.com/groups/billiardstl/
As for other rooms, there's Riverbend Billiards in Alton, IL - about 30 mins north of Downtown on the IL side.
What size tables do you prefer? Kenny's is a nice place, but only has one 9-footer. A ton of barboxes though. I haven't been to Hillborough yet, so I can't say how many they have.
The Break has 3, wait, 4? 9-footers and something like 15 barboxes.
Cue & Cushion has 15 9-footers, I think? Also a heated 3-cushion and a 10-foot snooker table.
Riverbend has at least four 9-footers, I think? Can't remember exactly, it's been a few years.
Haven't been to the other places already listed (ABC or Teachers). But if you're going to St. Charles, don't forget about Side Pockets, a ton of barboxes but again only 1 big table.