I assume you're looking for a general freshwater setup, not something species spceific like cichlids or discus. I have a 35g hex (not currently in use) and it was fine for a general mix, as long as you don't have many bottom feeders. You will want mainly mid-dwelling fish, as apposed to top or bottom.
Bottom
4-6 corys
1 snail
ghost or amano shrimp
Middle
10 small tetras - silver tip,diamond head, glowlight,or rummynose
5 platies, mollies ,or swordtails
Top
1 dwarf gouraimi - neon or powder blue
Hex tanks are great for angle fish . But I would only keep 1 as a "centerpiece" fish.
EDIT: You know you need to first cycle the tank, yes?