[Blitzen]

Mobo - Asus P5KC, Asus P5K Premium or MSI P35 Platinum - ABIT have the IP35. Nicer than the ASUS boards and ABIT support is FAR superior
CPU - Intel Core 2 Quad-Core Q6600 - Wait for a week or so. The new Quads are coming and will be faster, cooler and cheaper.
Memory - 4GB (2x2GB) Corsair TwinX XMS2 or 4GB (2x2GB) GeIL PC2-6400 Black Dragon - Memory is all much the sameness. Cantr eally go wrong here as long as it Corsair (dont like their RMA)/Geil/OCZ/Gskill.
PSU - 500W Enermax Liberty or 520W Corsair HX - Personal preference. Both are very good. Corsair slightly more powerful. Enermax superior quality (in my opinion...i have both)
GPU - 512MB BFG Technology 8800GT OC2 - New 8800GTS G92 will be on general sale the end of this week. All reports seem to say they are around the £200 mark and are faster, quieter and cooler than the 8800GT
CPU Cooler - Arctic Cooling Freezer 7 Pro - It'll do for a budget cooler
Hard Drives - 2 x 250 Gb Western Digital WD2500AAKS Caviar SE16 (in Mirrored RAID) - All much the sameness. Personal preference here with this one.
Keyboard - Microsoft Digital Media Pro
Mouse - 1600dpi Laser Mouse (Already Bought with Laptop and is most definitely up to scratch)