I've owned 3 Xbox 360s.. Problems up the ying yang..
I've owned 1 80gb PS3.. Never had a single problem with it. It even acted as my computer for awhile when my laptop died.
Personally though, there are no longer any games I will buy for 360. So I will be mostly a PS3 fan from here on. M.A.G., Dead Rising 2, the Ratchet & Clank series, they're all going to be on PS3 to my knowledge, and anything else is coming to PC. (AC2, Battlefield: Bad Company 2.. Does anyone notice there's a lot of 2's coming out?)
As for online.. I'm not in a position where I can get Xbox Live, so PS3's free online is great. I managed to acquire Live once though, because of my cousin, and he ended up getting Battlefield: Bad Company. (I let him borrow my 360 because I hated it so much, and I also had BF:BC for PS3) We played the same game on both the consoles online, and we both ended up liking PS3's online more.
If I had to recommend something.. I'd say forget about getting consoles, and just use the money to upgrade/purchase a computer.