I purchased and repaired mostly Dell desktops and laptops for work. We had Compaq, Gateway, HP Vectra and DEC desktops and Toshiba, IBM laptops. I liked the Dells the best out of all of them but their new laptops are pretty crappy. I posted about them here somewhere, the problems I had with them with heat and burn-in on the monitors. And they're much flimsier than they used to be, although prettier. If I were to buy a laptop today, I would probably go IBM.
chcr, my boyfriend bought a Sony Vaio a couple of years ago and I really don't like it. Besides the fact that it has no ps/2 ports on it, no parallel port, no floppy, a flimsy piece on the back that locks open when you open up the cover that's already broken twice, I had a bitch of a time replacing the keyboard when it broke. Sony has no support on their site for the general public (I've never seen better pc support than Dell's site) and were less than gracious when we called to order the new keyboard. I only figured out how to get the damn thing out by a fluke. I was hanging my head in frustration, staring at the keyboard when I spotted two tiny slivers of metal between the front of the keyboard and the case. When searching online for repair information on this thing, so many people said they same thing, that the Vaios are a bitch to repair yourself.