As a non-PC-windows-geek, the innards of a PC have always seemed a bit of a mystery to me. However, over the years, I've managed to do enough basic mods successfully... swap out HDs, hardware upgrades, software tweaks, etc.... that I now find myself confident enough to actually consider home-building someday, maybe my next PC.
So... from the viewpoint of the hardcore techno-geek (you all) who have done this several times over... what is the hardest part of building your own? Which part do you dread, and why?