Best Schooling Fish?

My favorite are harlequin rasboras

I 2nd that. This pic doesn't do justice with there beautiful coloring.

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Sids
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Rasboras next, then African 3 stripe glass cats.
 
Rummy Nose Tetra
Black Neon Tetra

I have both Rummy Nose and Black Neon's in my 55G, and they school nicely. They usually spread out a little, but as soon as either I or the angel that lives with them comes too close they all zip back together again.
 
Rummynose tetras
 
I have a school of Blood Fin Tetras that I really like, but after seeing the Rummy Nose pics . . . I have always fancied a school of neon or cardinal tetras as they are very colorful, but I dont think they "school" as tightly as other tetras in small numbers.
 
Dwarf neon Rainbows

Guessing you're suggesting Praecox Rainbows? If so, I just so happen to have a couple pictures to share, taken of my newly acquired fish a couple days ago. :)

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They're not constantly swimming that tightly together, but then I don't really have anything in the tank large enough to present a "threat" to them. They do seem to stick together a good bit of the time though, and are a lot of fun to watch. They're very active, and really color up once they're more comfortable with their environment.
 
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