I am very fortunate to have a nice new gym just next to my work. The gym is really great - it has two swimming pools (one of them is on the roof with the view to downtown SF), a small climbing wall (also on the roof), one racquetball and two squash courts, three badminton courts, volleyball, basketball and indoor soccer fields, plus all the regular stuff that usually gyms offer. They also have plenty of organized classes (like yoga, spinning, body pump, hip hop, kick-boxing and others).
I have to say that I was not impressed with any class that I took there (I tried different yoga classes, hip hop and body pump). At least I did not like any of them to the extent that I would be willing to reorganize my life in the way to be able to attend them.
So it seems that the thing that I do most often in the gym is playing squash. I usually play it one to three times a week, and I would definitely not mind playing it more often (even every day). I am also trying to force myself to start going to the swimming pool, but to be honest, I find swimming boring. However, as my plans for near future include learning scuba diving and windsurfing (or kite-surfing or maybe even surfing), it seems logical to start practicing swimming beforehand. So here, officially, I commit myself to go to the swimming pool before the end of the week. Kick my ass if I don't.
This is a picture of the gym taken on 26th of July 2007: