Title says pretty much all of it. To any of the more hardcore gamers out there, do you have any favorite 'game challenges' you'd like to share? What I mean by game challenge essentially is some way that you play the game differently than normal, or a mode you play to make it harder or more interesting. Such as low level, solo character, no damage, hard mode, etc.
Even though they can be quite frustrating I like to attempt them from time to time. Right now i'm trying a low level game, but I patched it so the enemies are all twice as strong to make it a truely badass challenge. Share any challenges you have done or are doing, talk about ones you want to try, suggest a challenge, or discuss your questions/comments on challenges here.