For all you Assassins out there, who has been your greatest mark and you got away with it?

I once killed 8 guards and got away with it. That's not really a greatest mark story, but it's something.

One of my top favorites was also an unorthodox assassination. I frenzied Nazeem and watched as all of Whiterun cut him down.

Do you mean the dark brotherhood contracts or just free roaming killing?
A always enjoyed killing Nazeem. Also i loved killing mogrul and his bodyguard in dragonborn.
I used console commands and made him a follower, asked him to follow me to near the earth stone, and i stabbed him and dumped his boddy in the sea, did the same to the bodyguard. guards didn't spot me.

also sometimes when im bored, i remove the npc's essential tags, and start killing randomly, once i killed everyone in riften without getting caught or spotted between each murder, it was epic..

I have a small feeling this could end up turning into a "This is how I killed Nazeem without getting caught" thread.

I thought the same but i enjoyed the method more than the target, in this case.

Thats hilarious!

how dare you! Stop right there criminal scum! You are now under arrest!

*after a long pause* Nooooooo!

Too my credit they were Solitude Guards, if that makes it a difference.

I'm sure that's acceptable to him.