Which faction do you like the most in Heroes of Might and Magic IV?

On Tron, Orcs and Centaurs are very strong. That's why I like Barbarians with Chaos there.

Well, Chaos depends heavily on the setup. Thieves + Trolls with Minotaurs is a difficult setup to play. And there won't be enough Orcs without additional generation.
By the way, that's when I was first horrified to learn that Trolls don't regenerate to full health, but only to 50 HP.