I love my PS3 and hooked up to Play TV and my media server, it's absolutely brilliant as it's so quiet, I like high def movies and there's some great exclusives and free online.
But in all honest, the price of the Xbox 360 is too compelling at the moment and recommend you get an XBox however I really do recommend a bit of research before you buy one because they notoriously break easily as they have bad (inconsistent) build quality.
You basically need to guarantee you get one with a certain chipset and heat pipe which is less prone to red ring of death than other models and quieter DVD drives.
Microsoft basically have different factories making Xboxs, some are better than others with better drives, better chipsets etc but just package them all up as "Xbox 360". Weird but true!
There's a new chipset coming (Jasper) but there's no guarantee they're in shops at the moment, so you're probably better off with a falcon chipset which is what I have and there's been no problem with it in 2 years.
There's a list of what 360s have what chipsets/drives here :
http://www.360drives.com/listYou basically look near the barcode and there's a LOT number and you just match it up to see what sort of Xbox you're getting
I wouldn't recommend buying a 360 from a retailer without a good returns policy, pretty much all 360s (non falcon) will die at some point and need to be returned to Microsoft for fixing (which is free in the first 3 years) if you're within a year you can normally return it to the shop you bought it and get a new one.
So yeah, I prefer the build quality and general usefulness of the PS3 but recommend for price that you go for a 360 if you just want some games to play together
.
Also Microsoft has some really nice xmas bundles with extra games etc out at the moment which are good value.
I would also recommend that you do not get the Arcade (cheapest) version of the console, it has no hard drive so you can't download demos which is a pain and the 20gb or 60gb console would be the best value.
Hope that helps (yes I am a nerd!)