Since i've been working at EB games (Australia's Gamestop) for a few months now, i've actually learned a lot about both systems. Both good and bad for each, but i've come to a conclusion.
PS3 is the way to go.
This is an unbiased opinion. Yes, i used to be a huge fan of the PS3 even though i didn't (Still don't) own one and i was naturally against the 360 for the same reason. When i started to work at EB i began leaning towards buying a 360 because let's face it, it does have a lot of games, some of which i'd really like to play but they aren't on the PS3. I was really close to buying one one day but i was too torn to finalise my decision and i ended up buying neither.
What changed my mind was this;
A PS3 requires a larger lump sum straight off the bat, but in the end it's cheaper. It comes with everything you need. Unless you buy the Elite edition of the 360 you really aren't getting your moneys worth, and even then, you still need to fork out at least another $100 for required accessories for decent gameplay, and that's just off the bat, and if you're interested in online play you have to spend 90AUD a year. I don't care if it has a better interface or is cooler, i'm not paying close to $100 a year to play my games online.
If you don't get the Elite edition for the Xbox then you don't get a HDMI cable, which costs 80AUD and you get half the HDD space as the elite. Admittedly the system is quite cheap, something like 447AUD, or 547AUD for the elite, whereas the PS3 is 688AUD (Comes with one new release game, 360's come with Halo/GoW). There is another cheaper alternative for the 360, but it's not even worth mentioning because the HDD space (Should i even call it a HDD?) is 256mb, and you'll save maybe three or four game files on it before it's full.
When i weighed my options when seriously considering getting a next-gen console (Wii doesn't count, it sucks), the PS3 came out on top. Unless you've got the spare money to throw around getting play & charge kits (PS3 comes with USB chargers) and Xbox live (As examples) then you're better off just getting a PS3. The only area where a PS3 fails is the price of the controllers, which are roughly $20 more expensive than the 360 ones.
In conclusion; get a 360 if you have the money and you really like their titles, otherwise just go with the safer option of a PS3. I could talk about how many fucking problems the 360 has had (Yeah the PS3 has had a few as well, not as much though), but everyone knows about them, so whatever.