Umm. I own a "True" Green Terror, a "True" Red Terror, an "albino" clown knife, that isn't doing to hot right now , a FM hybrid, a trio of network cories (C. reticulatus), some rarer/harder to come by betta tailtypes/color patterns. I used to own "true" Julii cories. I don't know if you consider all those "rare", but I know that they aren't the most common around me...
I'm sure some people on here will wipe the floor with my list
My rarest fish is probably my synodontis, since he's a hybrid, so there's probably very few just like him. Then again, that's not really rare... other than that, I guess my halfbeak. I don't know many people at all who have one. That's it. My rares are crap. XD
The rarest I have is some kind of variation of neon tetras. They look like albinos, but they have the skinny blue stripe like normal neons, and they area around their eye is blue like normal neons. The second rarest fish I have is probably black Kuhlie loaches.
My rarest fish are either my L stappersi (least common of my fish I've been able to find) or my Albino Bristlenoses (not found outside of the hobby and not as common as thenir normal brethern) so nothing truly rare or expensive.
I guess it would have been the rottkeil severums I had and sold on (for a pittance lol). Pah, wish I'd not got rid of them now. Mind you, they're not so rare any more.
Oh and my L203 volkswagen plec (RIP). They're not rare, but they were the least likely to be found available near me lol. And festivums are hard to get hold of too, so I guess he's on the list.
Well for in Australia my Anostomus Anostomus and Spotted Raphael are kinda rare... Dunno if a African Butterfly Fish is considered rare Lol well for outside Australia my Rendahls catfish is rare....
And I've got a gold form of heterandria formosa, don't know how common that is.
you don't often see the ordinary merry widow (phallichthys amates) in the shops either
I was offered some wild guppies at the weekend but had to turn them down. They were little beauties- who says wild guppies are colourless? they're a lot prettier than what you see in the shops.
Most likely my Parauchenoglanis guttatus- I'd guesstimate there's only a dozen or so in the UK, some of which are probably accidental imports with the (rare although rather more common) normal dwarf giraffe cat, which I also have. Other than those two, there's delhezi and the betta smaragdina.