First up, I'm biased, so take this for what it's worth. The 80GB PS3 has upwards of 80% compatibility for PS2 games. If you can still locate a 60GB PS3, then you're guaranteed near 100% compatibility. When I read about the new PS3's being made loosing compatibility, I located a 60GB at a Best Buy about 40 miles away. Bought it online and drove down to pick it up. It can do 1080p, but you need to buy yourself a HDMI cable first. BJ Wholesale Club had a bunch of 6ft cables for $20. They sold out pretty quick, next best was Radio Shack for $60 for a 6ft cable. Only thing is, not too many games have been released that go up to true 1080p. Usually see 720p.
Don't forget the PS3 doubles as a blu-ray player.
Or get a Wii. I actually end up spending more time on the Wii than the PS3