Thats prolly one of the hardest things in the world to do, and i fear i might have to say one or two in my lifetime. What do you say about someone in their eulogy if they were a fucked up person?
Depends on the kind of person you are. The definition of eulogy is: a formal expression of praise. So I guess one is supposed to forget about all the fucked up shit and talk about how good of a person they were underneith their hard exterior.
My boyfriend was supposed to write an eulogy for his father who died a few months ago.. and that man was.. pretty fucked up and mean in the end. He just had to remember him as a young man.. but it was hard to just forget about all of the bad memories. Still, he managed to write something nice, because he was his father after all, and he loved him.. But if you don't give a shit about someone, then don't bother to write anything for them, even if it's gonna "look bad". Never force it.
I guess you could say what a perfect asshole the person was, or praise how much of a prick he was the night you went out to dinner and he stole the tip off the table. You could always finish it off by stating how much you will miss his stealing, cheating and lying ways, how you will always remember him for his fucked up attitude.