Chinese Algae Eaters. Aggressive, ugly and after a while they don't even eat algae. I will never have the space to maintain a species tank just for one of them, and if I did I could think of better uses for that tank.
Can't believe both platys and corys made it on to other people's lists; I love their personalities. Funny how we all have different tastes.
Oh by the way, Dwarfs, what WOULD you buy? You seem to have been dissatisfied with an awful lot. I trust there are some fish that have lived up to expectation?