I've only ever used HPs. My parents had an HP desktop, then I nannied all summer to buy an HP desktop before I went to college. Then I sold that one because I wanted a digital camera more than a computer, and then a friend sold me her old HP laptop for $200. In Jan. I sold that old laptop and finally bought a brand new HP laptop from CompUSA.
I've never had troubles with HPs that I wasn't responsible for. I tinker and I mettle, so when I break something I don't blame it on the computer. The only time I did have a problem that wasn't my fault, I e-mailed HP and they contacted me within the hour with a list of solutions.
I've always believe that with ANY computer of any brand or platform, you get what you pay for. If you only paid $600 for a laptop, expect your computer to have crappier parts and design and not last very long.
My current model is HP Pavilion dv2050us. It came with Windows XP Media Edition but has a free upgrade to Vista and is a "Vista premium ready" computer (meaning I need no additional hardware for the upgrade). It's very small, very light, has a built-in webcam/digicam, plays and burns DVDs, 2GB RAM, dual core processor, 160GB hard drive, remote control, media card slots, built-in wireless, ethernet port, firewire, VGA, S-video, various audio ports, USB ports, a 6-cell battery that lasts 4 hours playing music. I love it and couldn't be happier with it. The only con so far is that there is no PCMCIA slot, but I knew that when I purchased it and probably will never need one.
My default PC option is usually HP because I prefer the way they look and I much prefer their laptop keyboards to Dell and Lenovo. Since I've never had a major problem with one, I'll probably keep getting them unless I can afford a Mac or higher end "business model" PC.