Soul Eater is an amazing anime with a questionable ending, I still love it to death even though its a terrible ending. Pluto which isn't an anime but a manga doesn't have a satisfying ending to me at all which made me give it a 9.5 instead of a 10 but is still one of the best manga I've ever read.

If an ending is bad but the anime is all around enjoyable then it won't take away from the experience I had while watching it, but i'll still be upset about the bad ending