You're stocking is pretty flexible as you don't have any easily picked on fish (ie long flowing fins, poor eyesight, slow). You should be OK with most community to semi-aggressive fish as long as they aren't large enough to eat your neons.
A single Ram would be very pretty (just not a pair as they will either fight each other, or breed and take over/kill everything). Bolivians are known to be a bit friendlier and hardier than German Blue's.
There are a variety of gorgeous gourami that would work as well. Personally I wouldn't recommend the dwarf just because they have been bred with so many hormones that they are a rather immuno-comprimised fish.