Homeworld fans rejoice! The sequel is coming out soon on the Mac! (Even if the original never did.) This is most likely the most 'realistic' space battle game ever made. Forces you to think in non-terrestrial terms - meaning you have no up or down, and you have to plan attacks and defenses in spatial coordinates, which makes it a game like no other. One of the top three reasons I kept a PC. The other two were Counterstrike and Half-Life. Tres cool! More details here.