I have a one year old Dell Inspiron 1525 with Ubuntu.
Not the best laptop ever but at least since Ubuntu 9.10 ... 3D graphics worked out of the box (open-source, Intel), Wifi worked out of the box (not so on OpenSuse or Debian), the built-in webcam worked out of the box, practically everything is up and running as soon as you install Ubuntu, no extra configuration required.
Not only that, but I also got an external 3G modem from Vodafone, that also worked out of the box.
As I've said before ... there are plenty of configurations that are running just fine with Ubuntu, but if you're going to shop at random of course you're going to have problems. Heck ... my external 3G modem wasn't compatible with Vista out of the box, you had to search for an updated driver on the Internet.