I'd say X3:TC:AP is the largest game on Linux so far. I haven't given it a try to see if it runs better on Linux, the install is larger than my home drive at the moment. And I am out of hard drive bays, and steam Linux can't recognize portable drives when you try to add another library.
He who stumbles around in darkness with a stick is blind. But he who... sticks out in darkness... is... fluorescent! - Brother Silence