This is how I learned about 40k and got into the hobby itself. I'm broke but it was worth it. You may find yourself repeating after me, I've found a few others who have.

FOR THE EMPEROR!!!/10

Seriously though, this game is awesome. A little rusty compared to SoulStorm (which is what you need to get + the MODS!!!), but this is the original. Seeing units in an RTS melee each other to death in spectacular execution animations was thrilling, and I got to learn just what was the grim darkness of the far future!