If it was my 33 gallon tank, i'd put the rest of my convict fry. I have a new batch everymonth . ahhhh. lol
But anyhow if i was starting a new tank, i'd probably go with some cichlids from south america. i like keyholes, since they are the closest you can get to community fish with cichlids. um.. i might put an angel or 2 as the centerpiece.. tho i'd probably end up getting a bigger tank just so i can get more angels.
Are you looking for colorful fishes? or maybe one or two big fishes? It all depends on what you want. a planted tank? with fake or real plants? etc. tell us how it all goes.