I have an Olympus TG-310 that leaked while I was using it in like 6 inches of water. This was after using it in deeper water (snorkeling depth) multiple times. Olympus replaced it under warranty. It has never been a favorite, however; photo quality (both under water and above) is not its strong point. However, I only paid about $120 for it on sale at Staples.
I later found a Nikon AW100 on clearance for ~$100. It takes much better photos and video, both in the water and out. However, its retail price was almost 3x the retail price of the 310. So you get what you pay for, to some extent. All of the "rugged" cameras use roughly the same seal design, although I do like the Nikon lock better than the Olympus one. All else being equal, I would go with a Panasonic, but I can get by with the Nikon.
A much cheaper option is the DicaPAC waterproof soft cases. I have a couple of them, and they work pretty well if you want to use a standard P&S underwater but not shell out a ton of money for a dedicated one. You could even use one for extra protection on a waterproof camera.