Personally I've found that HP and Dell laptops have good support for Linux, almost all the PC's I have tested have run just fine without any major pains
I agree. I have a Dell Latitude E6420. With its all-metal case it feels even more sturdy than the Thinkpad T-series.
Like most Thinkpads, the E6420 has is easy to disassemble and upgrade.
Except for the fingerprint reader, everything works out of the box on Debian. The laptop also ships with a pre-installed Ubuntu.
Acceptable keyboard and display, touchpad+trackpoint, optional built-in Smartcard/RFID reader, VGA and HDMI port.
It is also very silent and cool most of the time.
At first I was sad that I couldn't get a Thinkpad at work. However, after having spent one year with the E6420, I definitely prefer it over any Thinkpad and Macbook Pro I previously had.
I have a Dell Inspiron n5110 laptop and although bumblebee works fine for me, I have a video tearing problem on Ubuntu no matter which graphic chip I use. When I play a video file, it becomes like this[1]. So I wouldn't recommend buying an arbitrary Dell laptop without enough research.
I'm using HP Pavilion m6 running linux mint 14 for last 5-6 months. Very happy with the performance. I use it only for development and browsing etc i.e. no games. I've turned off the dedicated graphics card to get better battery life. I get about 6 hours on full charge. Not bad for 15.6 inch screen.
