Similar to Alpha Geek and uber geek, but specifically referring to someone who games excessively, or is focused on gaming, moreso even than other gamers around them. The person in a gaming circle who puts the most time and effort into the game or preparing for the game, regardless of whether or not they have a life outside it, although, that is usually true to carry the title as a compliment and not something more derogatory. Generally this refers more to people who play pen and paper RPGs or LARPs or miniatures rather than computer gamers.
You painted 257 miniatures in one night? Truly you are the Über Goober.