I've still got my Dell from 6 years ago.
5 years ago, the DVD drive failed for some reason, not even the Dell tech knew why. He gave us a new drive and IDE cable - the same drive's worked non-stop perfectly for 5 years now.
The only other component I changed was the hard drive in April this year, and the old one only broke because I corrupted it by accident and connected it to another PC, at which point it blew up.
So on the whole, that Dell is a beauty - still is, although it could probably do with a bit more RAM to speed things up a bit.
Dell are stupidly expensive though - I was going to buy an Inspiron 9300 or XPS Gen2, but it was just so expensive it was unreal.