i would swim in that tank with themFor a few million I'd just get a 1500 gallon tank and get a couple of red-tailed cats
Rarest fish ever...the aquatic dog.
hehe. Seriously though, it's probably the great white shark. Ok, so it's not exactly for the everyday aquarist But no one has successfully kept one alive for more than a couple of months in captivity. It's a "holy grail" not because it's rare (which it isn't), but because they're hard to keep.
p.s. the dog picture's not mine, btw. don't freak out on me.