The hard drive in my brother's aging (circa 2003) Dell tower finally gave up the ghost, and given that he just got his first full-time job and that the computer isn't really worth repairing at this point, he would like to replace it. Right now it seems he's torn between getting a laptop and my offer to build him a new tower (I've already built 2-3 systems already, so experience isn't really an issue here). He doesn't game on the PC all that much, but it sounds like he really wants a PC that is going to both be fast and responsive and last him several years, so we are looking mid-high end.
However, I haven't been keeping up too much with the last 6-12 month's advancement in the tech world, so feel free to suggest any changes to make this build even more compelling. Really the only four variables I don't want changed are the <$800 price, an Intel-branded processor, a NVIDIA-branded graphics card (tends to be much more reliable / compatible than ATI cards, in my experience) and a microatx form factor (space and noise constraints).
Just a copy and paste of my other post for people asking for a $600-800 computer, but you coud probaly change the graphics card to a nvidia one, then assuming you need the OS that would get you to about $800
Edit: Didnt really read the part where gaming will be the basically the last priority...so you could probaly just not buy a GPU and use the onboard graphics. But if you want a graphics card i found this NVIDIA card.