The Xbox360 owns a large share of the gaming market, with easier to program (and normally better-running) games, and more exclusives/extra game content. The only problem I see is what's to come in the future.
I think that things such as controllers, microphones, and internet gaming as a case of preference (i.e. Do you want to pay to play?). Sony is coming out with Home soon, which could be a competitor to XboxLive.
In the cheaper price, the xbox 360 has a lot of shortcomings compared to the PS3:
For instance, the most recent failure rate %age was somewhere around
16.4%. Compare this to the PS3, which sports about a 3%. I have personally had no experience with Microsoft customer support, but I’ve seen some pretty mixed emotions.
The PS3 comes with lithium ion rechargeable batteries for it’s controller, which currently (waiting for Dualshock 3) is lacking in the rumble department. The 360’s controller
can fulfill your rumble desires, but requires a battery pack that is sold separately.
The 360 also lacks built-in wireless capabilities, and the ability to read HD-DVDs without an attachment (though HD-DVD is sorta dead now).
On the gameplay end of things:
The PS3 is somewhat famous for it’s stuttery frame-rate, texture problems, and poor porting. Once developers get more acquainted with the system, I can see this stopping.
The PS3 normally has better audio (not that big of a deal unless you sank a lot of money in a nice system), and better scaling of the darker colours (mostly black :P).
Ps3’s SIXAXIS function is generally underused, underdeveloped, and sometimes outright terrible (see Lair). Though I feel it was used properly in some games (i.e. Folklore).
The 360 does have gamerscores and achievements, so you can show off to your friends!
On a final note:
The thing that really weirded me out was how fast that Microsoft dropped the original Xbox when the Xbox360 came out. Looking at the playstation 2, Sony continues to produce games (albeit sub-par to the 360, and PS3) on a regular basis. If this is any indication of the future, I would
personally go with a PS3.