Prize-level F1 "Zaire blue" frontosa, blue torpedo sharks, mormyid longostiris (or maybe rume--even Oddball can't tell for sure cause we don't know the source), tigrinus merodonotus, and recently thanks to Wes, Papyrocranus afer "Starry African Knife fish" and Gymnothorax polyuranodon "yellow and black leopard eel". Not sure what's the rarest but I like me some rare weird stuff!