If you don't mind driving time, depending on where you're staying, The Billiard Den is going to have the only Diamond Tables in town.
Clicks - Marsh has been my home base for quite some time now, even if I have to make a pretty long drive to get there. Good friends and good competition keep motivating me to go out there.
If you're closer to the mid-cities then Volcano's or Rusty's in Arlington would be a good choice. Rusty's is a 24 hour place, so you're always going to find a game there.
Like TD said, there's going to be different days that the pool halls are going to be filled with players.