What Greek military hero do you admire most?

[M. Caecilius]

I'm less familiar with the Greek world than with the Roman one, and would agree that the epitome of the hero is Leonidas, but to add to your list (leaving aside the mythical Homeric heroes):

- Xenophon of Athens. The Anabasis is possibly one of the most fascinating accounts left behind by an actual soldier from antiquity, in my personal appreciation of course.

- Epaminondas of Thebes. Your examples are all Spartan, so I assume you won't like the nomination of the person who cost the Lacedaimonians so dearly, but he was a great general and innovator.

- Alcibiades of Athens, though I hesitate to name him, as he could be considered more of an anti-hero than a hero, and his reputation is not entirely military. Pity for Athens he was not sent to Syracuse, though.

- Xanthippus of Sparta. Even though he fought most famously for Carthage, not for any Greek city, he was a Greek. He was also quite successful and resourceful, and his alleged death by treason also makes the stuff of a hero.

Overall, though I'd only put Xenophon in the league of Brasidas and both behind Leonidas.

Edit: for some suggestions, C. Iulius came in first whilst I as typing!