In particular, the Star Trek: Armada 3 mod has an astonishing level of polish and attention to detail put into it in fact, it's probably the closest any game has come to actually simulating the experience of controlling a battle from the original shows, even out shining some of the official Star Trek games, like Star Trek Online. I recently purchased Sins of a Solar Empire: Rebellion via the Steam sale, and while the base game itself is great on its own, I found myself really blow away by how good some of the mods for it are.