If you like the schooling then tetras are hard to beat. I like the Harlequin rasboros as well as they are a great mid-level schooler. A few Rainbows also for the character and some harmless chasing. Keyholes in my experience are OK for community, but wouldn't say they are high on character. and I'm like Ryan with rams-love them but- OK getting them up to spawning stage then they always seem to fall over on me, but pair of apistos sure add character to any tank. A couple of Angelicus, zebra or that sort of loach will play with other all day.