I bought a 360 a few weeks ago, and I chose an Xbox simply because it had more of the exclusive games I wanted. The PS3 has God of War III (coming soon) and WipeOut HD which I’ll miss, but not much else for my gaming preferences. All other “must have” games are cross-platform, so they’ll work on either one.
As for your other concerns, the recent model Xbox (check Google for ways to identify the Jasper revision) should be a lot more reliable than the earlier versions (smaller, better integrated chips; they also use much less power). The 360’s controller are also wireless and work flawlessly.
So if it’s mostly for gaming purposes, my suggestion would be to check out which platform has the exclusives you want more (and there seems to be less and less exclusives as time goes by); I use the site MetaCritic since they aggregate all reviews for each game and tend to give a pretty good picture of how good a game is.
If you prefer a “media center”, the PS3’s Blu-Ray is a good deal. It’s the best BR player on the market and can be updated via internet. The 360 doesn’t play HD discs (not since HDDVD died, anyway…) but can stream HD from a PC on the network. There are a few codec issues that might be fixed in a future update, but the PS3 works out-of-the box NOW with BR discs.
For the online aspect, Xbox Live currently rules. While the Gold version is not free, it offers the best service overall. It’s fast: game patches download quickly; 1GB games demos can be downloaded in 3-4 minutes; there’s Xbox Live arcade, which offers a whole bunch of games for low prices; you can also download TV shows and movies. If you’re in the US, you can get a NetFlix account and stream movies directly to the Xbox (it really pisses me off that that service is not available in Canada). The multiplayer experience is also more uniform on the Xbox side, as all games support voice, matchmaking, etc. Sony’s service is currently free, but they haven’t yet made up Microsoft’s 5 years headstart.
Personally, HD movie-wise, I’m gonna wait one more year to see how the various streaming solutions progress vs. BluRay. If at that point I decide to get a BluRay player, I’ll probably get the PS3, which should’ve come down in price at that point.