I had two Compaqs in a row die within weeks of the warranty expiring. This was about the time the HP bought Compaq so there may have been a few bumps during the transition.
I have a Dell laptop that I have never had a problem with, but it is only a couple of years old (longer than my Compaqs lasted though). Dell customer service is the pits, but their products seem to be pretty well built. I have an old Dell computer (at least 6 years old) that I use in New Orleans for intenet access.
We had IBM laptops at my office, and they were not reliable at all. We all went through them like potato chips. I had a screen go bad, multiple hard disk failures, modem burnout, power cord problems, etc. That wasn't just me - everyone else had problems too.
My sister has a Mac powerbook. She's had a few problems with it - lost her hard disk most recently. It's been in the shop about 3 times, but it is 3-4 years old.