On Cue Billiards in La Mesa is probably the best room in the San Diego area. They have a really strong Monday night tournament with Louis Ulrich and a host of other good players. As someone mentioned, try to make it to Hard Times in Bellflower. They have a huge Sunday tournament which some strong pros (Oscar Dominguez, Ernesto Dominguez, Santos Sambajon, Morro Paez, Louis Ulrich, Dave Hemmah) play in on a regular basis. Hard Times is my all time favorite pool hall.