A relatively easy win for Half-Life 2, it seems, since my biggest favourites of the decade, and in fact ever, were left out. Uncharted 2 is the only competition, but ultimately it's Half-Life 2 I have recurring interest in playing again and not Uncharted 2, and it's the more influential game too. Halo is even more influential for sure, but despite three or so attempts to start it, it's one of the few games I just haven't been able to get into at all. I couldn't in good conscience possibly vote for it unless specifically asked for an influential game.