id say my ray and my bucket mouth cichlids and my flowerhorn... they are in my sa ca tank it has 5 fire mouths 1 green terror 1 flower horn 1 jack dempsy 1 rainbow cichlid
I think the rarest fish I currently have would be my Tahuantinsuyoa macantzatza, I've only seen a couple on this site. That said, they are available pretty often from my LFS (The Wet Spot) and cost under $10 as juvies.
Through 7 pages I've seen 1-2 pics. This type of thread should be full of pictures.
That being said I don't have a pic of my rarest either, haha. Its nothing crazy but I have 2 Aulonocara jacobfreibergi "Eureka" with a large amount of orange coloring.