I couldn't resist chiming in on this topic. As a game journalist who's logged multiple hours with many of the new PS3 games as well as the proud owner of an Xbox 360, Nintendo Wii and mid-range PC (soon to have a shiny, new high-end gfx card), I have to say that IMO this whole debate is flawed at its most basic level because of the fact that the PS3 really isn't all that great just yet.
Hear me out.
Under the hood, it's definitely got some serious graphical and processing horsepower... no arguments there. There isn't much out there yet in the way of games, unless you like racers (Motorstorm and F1 Championship Edition both look and play oh so sweetly), that hasn't been previously available on other systems (i.e. Oblivion). The visual difference between the 360 and PS3 at this point is marginal, and the 360 actually comes out on top in a surprising number of cases. PS3 owners are going to be waiting at least 3 months, probably closer to 6-8, for any of the serious PS3-exclusive releases to drop (FFXIII, MGS4, Mercenaries 2... and that's pretty much it). The Blu-Ray is a nice addition, but looking at Sony's track record with introducing new media (Betamax, minidisc, UMD) and taking into account the fact that HD-DVD not only has a release lead on Blu-Ray but it also has far better implemented features, and Blu-Ray starts to lose some of its luster.
For serious gaming, nothing can beat a hand-built PC. But to weigh that against a PS3 feels like no contest to me at this point. If you really want to go for a next-gen console, the 360 is definitely the best choice. If you add in the HD-DVD attachment, it brings the price up to $600, just like the Sony system. That said, with rumors abound that a 2nd-gen Xbox 360 is in the works, complete with (finally) an HDMI interface and built-in digital video recording capability XTiVo 360 anyone?), your best bet is to either wait and see what a few months brings, get a gaming PC or - if you really can't wait and want some new games to play with - go for the comparatively cheap Wii (if you can find one), which is going to have a hard time NOT revolutionizing the way we think of and interact with video games. And just for the record, I did love my old PS2; I just think Sony dropped the ball in a big way on this one. I'll step off of my PS3-hating soapbox now... thanks for providing a forum for me to rant about this.