What tank size? Danio are incredibly active and very interesting to watch, but they need at least a ten gallon as they;re very active fish. You could also do a bunch of guppy, either all males or 2-3 females per every male.
Or instead of neon tetra, try cardinal tetra, they're a bit more colorful, their red line travels the entire body were as the neon's red line stops mid body.
Or, once again his depends on tank size, you could try a school of otto cats, great cleaners who have to be a group if at least three. Or perhpas a school of cory cats, floor scavengers, they need groups of 4-5.
Best of Luck!
