I was recently RP'ing an Assassin, and I want to get my bounty cleared without joining the thieves guild (or when I'm rp'ing other characters, because all my characters tend to be more evil :/). I know there are people who will clear your bounty once with select quests, but what I'm really asking for, is if anyone knows some mods where I can get my bounty cleared. I wouldn't mind any thief like mods, as long as there's no guild required. I'm also thinking of installing the "Regionally Known Criminals" mod.

uhm,haven′t played in a while, so could miss out on the details.

anyway with regional criminal mod you can confess to the crime to guards (found the readme to it).For rp-reasons my character usually do that in regions where it isn′t burdened with a bounty,and approach a guard there.
from the mods readme:
"Now there is a new topic "confess to a crime". With this you will be able to tell the guards about your crimes, so you will be able to pay your bounty and clear your name in any regions".