I love targeting unusual species on flies. It presents new challenges and learning curves. I've said before that I will give up fishing the day I no longer learn from it. I don't see much chance of me quitting before I die.
So her is my list so far in the short time I have been using flies to fish, in no particular order.
Red Hoarse Sucker
American Eel (Technically it ate the fish I was landing, but hey...)
My goals for next year:
Bigger Stripers, Blues, and Suckers
Any Swordfish Species
All those crazy little Japanese salmonids
...... I could go on for ever. I may need two lifetimes to get it all accomplished!