Dell's older laptops used to be pretty horrible, but they've made significant improvements and their latest line of higher end business laptops are pretty darn nice.
I've had decent luck with mine. I did splurge for the extra warranty coverage, so the one time I did have a broken drive, I had a guy at my door (in Innsbruck, Austria) the next morning with a new drive.
I use a Dell XPS 15-inch with Ubuntu, and I've had a few cosmetic issues but nothing that impaired functionality. Overall I'm quite happy with it and would recommend it to the OP.
Seconded. I had a Dell, admittedly a low-end one, and it was dreadful. Crummy build, large pixel size, a ton of bloatware (not that that's relevant if you're going to put linux on it). And the wi-fi under Ubuntu was extremely flaky.