get a script to do it, or just submit yourself, but gaming.reddit: what's new in gaming <- is huge... and a really tight-knit community. mention your site in some comments, etc, submit some posts... or you can run ads on there relatively cheap.
Facebook:
20 Different advertising campaigns that lead to a direct link to that hub page on your site. Find the 20 most popular games this year, target, win.
SEcond,
Your site doesn't look like its about gaming. You don't give a nod to the hardware (Controllers, Xbox logos, TV's, etc) or the software (Popular characters, cartoony looks, explosions, whatever)
Just some thoughts. Best of luck. Looks like a great concept.