E8400 with P5Q has been a mouth watering solution a few years ago. It is still a great setup but mostly if you have a deal or a friend who offers it at good price.
For new toys, you can get faster for cheaper.
For example the E8400 is at about 170$.
For about 130$ you can get either a PhenomII Tri core or an AthlonII Quad and invest more on the videocard to get something like a Radeon 4870.
From there you can either get a budjet motherboard with DDR2 Ram such as an AM2+ M3A78-EM with a better CPU like a PhenomII or an AM3 M4A785 with DDR3 Ram with a cheaper Athlon2 Tricore and upgrade that setup 1 year later for latest most cost effective cpu.