i have both the 360 and ps3 and i actually trust my 360 more. i had a ps3 break down on me already which was outside sony's one year warranty, so i had to spend $170 to get it repaired. my xbox has been working fine for a couple years now and it stays a lot cooler than both the ps3's i've had. i find the ps3 gets considerably warmer during use than the xbox ...and when it comes to heat and electronics, that's never a good thing.
the xbox has been greatly improved over the last couple of years. the only 360 models that really had a lot of problems were the first ones that came out when the system was first released. that model was named 'Xenon' and was almost guaranteed to fail. microsoft began making new models of the xbox that were more and more reliable and the current one that's out is called 'Jasper' which is a lot more reliable. i've actually read articles that states the Jasper as having a lower failure rate than the ps3 ...whether its true or not, who knows, but i don't really doubt it. my xbox is the 'Falcon' model ...which is the one that came out before the 'Jasper' and was also thought of to be pretty safe ...which is why i finally bought one.
Microsoft also have a 3 year extended warranty for the red ring of death and e74 error ...so i really wouldn't worry. too bad sony wouldn't throw their users a bone like that for the 'yellow light of death' which is actually fairly common among ps3 users. more so than you'd think anyway ...and that's what happened to mine. i was forced to spend another $170 to get my ps3 fixed after spending $650 when it first came out. thanks sony for the support ...i spent roughly $1000 for my ps3 so far ...how nice.
so anyway ...if you want an xbox360 get one and don't worry about anything. the new 'Jasper' systems have been on the market for a year or more now and are quite safe. even if you do happen to get the red ring or e74, you're covered for 3 years ...unlike sony.