lol @ mjewel, that was hilarious and you had me laughing very hard, so hard I spit coffee all over my keyboard, which is now ruined and I had to grab an old one lmao. I should file in small claims court to get my $45 back j/k. It really did fry it though lol, but, I'm buying a new one today anyway since it was already starting to go lol. Back on topic, I would go with what a few other posters recommended. You two could dominate the market if you do it correctly. You need to stop being petty, shoot the guy and email (unless you know him personally) and offer to make amends for anything you have done, offer to forgive for anything he has done, and go into this together. With those two domains you could, theoretically, dominate the gaming forum niche, which would turn into a VERY good investment for you if you monetize it correctly.
I agree you should have bought the dot com with your other name as dot com is popular, second if you do want to proceed you can file a UDRP and try to get it back but in your case it is a slim chance or getting it.
looks like he got the .com from a reseller as it was reg four years before the .co.uk domain, if i was you i would buy the .org version and bury his site in searches...