The two 40GB consoles I've owned previously were in horrible condition bought second hand from Blockbuster. The one I had's fan would be super loud after a half an hour or so play on Uncharted. I was so paranoid about it dying that I just got rid of it and went back to the 360 (this was in 09 when I had my first PS3). At least 360s were cheap to replace at the time. That PS3 cost me £200 or there abouts I believe.
My current 120GB is perfect, bought it second hand from Blockbuster again but made sure I got one that was in good condition. I try to keep the console and my TV unit clean of dust as it's a bastard.

Only issue I've had with this 120GB console is a few freezes here or there. Nothing major.
