I got my X-Box 360 back in December of '08. Fortunately, I haven't had any problems. Don't know if it was because it was one of the newer-generation consoles, or if I was just one of the few lucky ones.
Now, as someone said before here, it can be about caring for it properly. The 360 has an interesting ventilation system. It's got openings on
all sides, so simply sitting it vertically doesn't make use of all the vents. I have it horizontally (also because I'm OCD about the discs/drive getting screwed if I make a mistake inserting it vertically) and it's currently sitting on a small box. This means all of the vents, above, on the sides, and underneath are exposed and can pump out that hot air. Intra-Coolers be damned. No need for it if you can live with your 360 sitting on something.
So basically, the system's on top, and a smaller box is underneath to give the underside vents space:
_______
(______)
[__]
Dunno if that's helpful for anyone, but my console's crossed the two-year mark. I also don't play it too much these days. Every now and then, I get on to play some Skate 3 for an hour or two to blow off steam, then usually do something else.
Either way, both consoles have their issues and supposedly-eventual failures. So why beat around the bush if the PC always has them beat
?