shrimp and snails are not fish!!
my first tank was a mini-bow 2.5g, a betta is great because u do not need air pump, red claw crabs are awesome, they laid lots of eggs in the 2.5.
if you want something dfferent/interesting. pea puffer ftw! I love my lil' pea puffers. way cooler then tetras, second choice would be cherry red shrimp. mine are pretty indestructable as well.