"Bartolommeo Colleoni", Verrocchio. Venice 1479 (s)
This magnificent statue of Bartolommeo Colleoni, a Venetian general, illustrates the great standing held by Verrocchio. His fame was so great that the rival city of Venice commissioned him (a Florentine) to produce this equestrian statue.
I have seen this one in Venice, it's difficult to miss, and very, very impressive.