Topwater Schoolers

Hatchets are the only pure top dwellers that I've seen.
Glass bloodfins count there as well. I've never seen my glass bloodfins to use the mid section. They were at the top most of the time chasing each other around.
 
Have you consider Copella Sp. (splashing tetra) or Nannostomus Sp (pencilfish, not as active as splashing tetra though)?
 
Hatchets are nice, but they jump a lot and tend to disappear one at a time unless you cover you tank (and I mean completely cover it) Personally, I think you should look into some of the danios, a lot of people overlook them because they are so common, but there are a great deal of rarer danio species with some very striking colors and unusal patterns.
 
They're a bit smaller than some of the other suggestions made so far but I love my Furcata rainbows. They're almost always in the top 1/4 of the tank (except occasionally just after feeding looking for scraps they've missed), they're pretty social, constantly interacting with each other. And they have these bright blue eyes you can see from across the room. Just another suggestion.
 
I just got 5 harlequin rasboras today and I love them! They are really pretty and active in the tank. I got them as dither fish to make my dwarf gouramis less nervous and it's working! I think you'd like them :)
 
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