Well, do you want a community tank, a semi-aggressive tank, what?
In a 34 gal tank you could do a pair of kribs, maybe a small pleco (think bristle nose), a nice school of tetras (Rosy tetras are great, as are black neons and rummy-nose) or small barbs (cherry barbs are great little fish, but they don't school very tightly), then maybe some hatchets for the top level. Add a few caves of driftwood or rock, plant it heavy (real or fake) and it would look really nice.