Hardware for Blender

Blender uses the video card for the 3D display, but uses the cpu for rendering, so a good, possibly multi-core cpu is recommended.

See this rendering benchmark for dozens of hardware:
http://eofw.org/bench/

This is the list of systems in use and supported by active Blender developers:
http://wiki.blender.org/index.php/Dev:Ref/Supported_platforms