Fun Assassins

I haven't played many assassins before, and I'd like to find one to add to my champion pool. Whether the assassin is good in the current meta or not isn't an issue; I'm mainly looking for a champion that's both fun and satisfying to play. I understand that what's fun and what isn't is subjective, but I'd like to get some suggestions regardless.

In your opinion, who are some of the most fun assassins? Feel free to list more than one.