It's really a personal choice. I love my 360. Regardless of all tho problems associated with them, PS3 has them as well.
You may have to pay for XBL, but you get what you pay for. The marketplace is amazing. The interface is great. The controller is great. There are endless games for it. Backwards compatibility for the most part. The PS3 has nothing as far as I am concerned. Little Big Planet and Meta Gear Solid 4 were the only reason I was going to get it. The Blue Ray is no big deal. It's great for movies, horrible for games.
The XBL marketplace is enough to usually grab anybody. Besides, XBL is only $50 a year. What do WoW players spend? $120? And the game library alone is better then the PS3's.
Xbox Live is 360's biggest advantage and Blu Ray is PS3's biggest advantage. Ultimately you should choose the one with the most games that interest you, unless superior online play or Blu Ray is a must-have for you.
Xbox 360 has the advantage in terms of gaming library, online services, and price. PS3 has Blu Ray . . and that's about it. It's technically more powerful than the 360, but no games have really abused that yet. At the moment, 360 is the clear choice over the PS3.
I am finally getting around to getting the 360. My friend has a PS3 and I wasn't all that impressed, surely not enough to go out and buy one. I'll save a little money and get the system that has more games that I'll enjoy.
Ehh, as much of a Sony loyalist that I am I was very disappointed in the PS3.
You can't dispute the fact that the PS3 is better than the 360, but how long did it take Sony to jack it up? And the price is just not worth it. It's like pitting the PS2 against the Dreamcast. If the price went down, or if the PS3 had a larger community I'd be all for it.
Remember, it's up to you, but at the moment the 360 is still in vogue.