Of my current stock of fish it's my dwarf puffers. I just recently got back into the hobby and had never kept puffers before so I decided to get a pair for a planted 10 gal.
I think they are awesome looking fish but I was skeptical before I bought them just because of how small they are. These guys turned out to be some of the coolest fish I've ever owned. You get a ton of personality in an itty bitty fish.