Assassins. Hail Sithis! (And screw Nocturnal)

depends, my thieves wind up being assassins while exploring/questing due to sneak attacks... so slippery slope that leads into the dark brotherhood easily. After all if you didn't do something wrong, then nobody would risk hiring the dark brotherhood to kill you.

Okay I know a couple marks are iffy, but ya never know. That poor ol beggar may have assaulted someone in his demented state, or the lady hiding out as a serving wench could very well have been a bandit previously...

Thieves only take your toys: Assassins take your life!

Thieves. I like stealing everything from each hold palace and dumping it off Darkwater Falls.