[LarryMade]

Linux? Get one with an Intel or nVidia graphics chipset (if you want graphics speed, go nVidia) avoid ati/radeon - its support on Linux has been touchy, the drivers have a long history of installation issues.

if you want speed again i5 is a good minimum, don't skimp on the processor, you can't pop in a better one if its too slow... you can always improve the drive/ram later - make those less a factor.

drive if possible SSD, but then don't make it a major priority as that can be swapped out on most wintel machines.

Just about any distro should work fine, the only main sticking point for Linux users are the graphics chipsets.