I've got both (actually I have every single system since the Atari 2600 with entire collections for each). I've never considered myself a fanboy, I go with the system I think has better games (Though I still love my Dreamcast). In terms of capability the PS3 does edge out the Xbox360, however, it is harder to program for, but the same was true for the Xbox360 a year ago. Right now the games are visually similar. As programmers get into the metal of the PS3 I think it will eventually edge out the Xbox360 in terms of visuals, but its going to take some time. But here is the monkey wrench, popularity dictates whether or not the programmers are going to take the time to learn the system. Its not always the better system that wins out in the end. (Ah my beloved Dreamcast
) This latest console generation was the first one that I didn't wait in line over night or pre-order (pre-pay) a year in advance for any system launch (I've done that for every system since the PS1). None of them brought to the table any revolutionary game or graphic leap, nor did any tempt me with their meager software libraries. I eventually picked them up as the prices came down and the hype died down. If I had to choose only one I would look at what type of games I like to play (now and in the future) and see what each system had to offer. There are also pros and cons to both systems that need to be considered.
Only the higher end PS3 will continue to have PS2/PSOne support. The newer budget model has had that capability removed, something to consider. Also, if your HDTV (if you have one) doesn't support 720p you will have to put up with 480p max on most PS3 exclusive games, it doesn't upscale. Sony is really pushing the 720p format so this is probably going to be the case for the next year or so (PS2 and PSOne titles do get scaled to 1080i as do any BLURAY movies). The PS3 exclusive software is bleak for this xmas season. Lots of multiplatform stuff coming out, but no exclusives. Ratchet and Clank is the last one for this year. Next year will see Metal Gear Solid 4 and Gran Turismo. Its online service is simplistic, but does offer downloads of full games (Warhawk is the first and only so far). It is BLURay capable out of the box and has wifi built in. The controller doesn't have a rumble feature (though that is changing) but it does have the 6 axis tilt sensor which is pretty cool if used correctly. It also sounds like a jet engine as it gets hot. One other item to mention, it doesn't have connections for old PS2/PS1 peripherals. None of the older controllers work on it and the new controllers are blue tooth so any wireless PS2 controllers you have are not gonna work. Also, no place to plug in your memory cards.
The Xbox360 has hit its stride, but it also suffers from some negatives. While its download service (Xbox Live) is incredible it is handicapped by a limit on downloadable content size and isn't free like the PS3's. This means it won't be offering downloads of full games, but it does have great selection of movies, TV shows and other goodies for a price. Games look great and can be scaled up to as much as 1080i and there are also many to choose from (BioShock, Halo 3 are must have games), however you are limited in backward compatability. Only certain Xbox games (Halo, Halo 2 and Barbie Adventures to name a few) can be played on the xbox360. You also have to purchase an HDDVD add on in order to get HD DVD movies and you also have to purchase a separate wifi adapter.
Don't let the price difference fool you. They cost about the same when its all said and done, the only difference is the Xbox360 lets you choose what you want, the PS3 gives it to you all up front.
When I chose to purchase a game and that game is out on multiple platforms I typically choose the Xbox360 version simply because my HDTV can't handle 720p, the downloadable content is easier to get to and the controller has the rumble feature (though the new PS3 controller will have that eventually).
I noticed you didn't mention the Wii. Don't dismiss it. It can be a fun system. System wise its an overclocked Gamecube, but it has a unique party play quality. The Wiimote can be kinda silly, but it makes playing some games ...exciting for lack of a better word. Party games are all the rage, but very little substance. Its the one system the family or your friends can pick up and play at any point in time and have a blast. Thats the gamble Nintendo took and it seems to be paying off.
Sorry for my ramblings, I hope they were helpful and good luck in your decision.
