build your own rig.
get yourself a nice case, a nice i7 proc, id recommend the sandy bridge series, 8 gigs of ram minimum, 16 if youre doing heavy video editing, an ATI Radeon HD 6970 video card (maybe two in a crossfire array if you’re rendering full HD video) and some biiiiiiig hard drives, and an SSD to run your operating system and essential software. its expensive, but trust me its worth every penny. i’ve built all of my computers and they work better than any stock computers ive ever used or owned.