Create a hardcore character and kill Diablo on inferno.
Rules are:
1: You can only wear gray or white gear.
2: You can only use Left and Right mousebuttons.
3: You can not use any followers.
4: You can use potions.
5: You can use healing wells.
6: You can use shrines.
I'm not even going to attempt this myself, but i bet there's someone out there who will