That really depends. There are fanboys/girls for every system, and everyone is going to give you their own opinion. I personally have an Xbox360, but i have a few friends with ps3's. I don't see the difference with blu-ray vs HD, but that's a big argument that the graphics are just so much better on the ps3. Tbh, my buddy who has a ps3 and I both have a few of the same games, and I see absolutely no difference in graphics quality. And another argument is the online. I know from experience that Xbox360 has a better quality online, even my buddy who hates the 360 and lives off of his ps3 agrees with me.
I think it really comes down to what system has the exclusives you like better. Because other than that, I see no reason you couldn't enjoy either of them.
Also, I believe that the 360 is cheaper. The games certainly are.
Anyways, as Unbreakable probably already said, Xbox Live is the backbone to Xbox itself. PS3 cannot live up to the status of it, even being free. There is so much more to Xbox than you will realize. Such as the higher connectivity to websites and radio stations, plus higher tech microphones designed only for Xbox Live. Not only this, but there is so much more.
I've never taken time to sit down and play Ps3, and what I said above is the reason why.
Well I don't know about cheaper Xbox 360 games, here they are the same as PS3, and Xbox Live is a rip off, where as the PS3 online is free, so they have their pros and cons, I would never use a kinect too that's what a Wii is for, so it just all comes down to your personal preferences