I'd love an albino jade goby. Never seen one, but it's on my list.
African Arowana
Pisodonophis boro (had one, but the wife freaked out about it)
Ornate bichir
acanthicus adonis (had one, got bloat)
Many of the fancier bettas that die when you sneeze but are prettier than gold
Super black DD angelfish with blood red eyes
Completely green (no pattern) Oscar
Channa sp. Assam
cyprochromis leptosoma
cichlasoma grammodes (the mini-umbee!)
butis butis
Most large catfish I've seen, I want.