The X360 has it so over the PS3 that it's hard to believe that the Sony fanboys still try to foist the idea that the Black Elephant is even a contender. And, yes, I own a PS3 - a 60GB model I bought as a future-proof Blu-ray player and because it was still backwards-compatible; a feature that Sony used to sneer at Microsoft for not having on 100% of titles before they decided that 0% was good enough for their customers.
Whether it's the superior library of titles; exclusive add-ons; better visuals and performance; an actual working online system worth paying for to avoid the insult that is Home and their own epic fail of online usability; superlative controllers; you name it, it's better on the Xbox 360 if you're looking to play games with your game console and not serve as suckers for Sony's movie format power grab.
That said, there are two big knocks on the X360 which M$ should address: the lack of included wi-fi and the exorbitant price tag for the adapter, and the reliability. While you can always run a CAT5 cable if it's close to your router, the RRoD problem is still a major PITMFA!
I bought my first X360 in April 2006 and it RRoDed on me about 11 months later and I'm not a heavy gamer. M$ had just extended the warranty period to one year and I was covered. They sent back a totally different unit (as the S/N revealed) which ran OK for about 15 months before RRoDing again; this time having the guts replaced.
A year ago, I bought a 2nd unit for home to play GTA IV on. It was a Falcon with HDMI and a lot quieter than the original design I kept at my girlfriend's. After perhaps 100 hours of gaming time, last December I picked up a Holiday Bundle 60GB model which went to my place while the GTA unit rotated to my g/f's for general service, mostly watching downloaded shows. The other night, just two weeks shy of its birthday, the darn Falcon started freezing and then promptly RRoDed. Three failures of two units of two designs in three years. Yes, they've all been/will be fixed under warranty, but it's still a PITA.
If your store offers a reasonably-priced instant break/fix return extended warranty plan, I'd get it to cover yourself because it's clear that there are still problems. It's really too bad, too, since other than this one MAJOR flaw, it's quite the awesome system.