Thank you @BarbieKiller for the nomination of Stiglitz.
I would like to nominate own maps as well. I just managed to release new versions for all four ET: Legacy overhauls (Splash Damage forums) and I'm quite proud of them. They have come a long way and I think they are quite stable. I don't know if this is within the rules as they are not the most played maps or technically played at all, since they have just been released, but seeing how the time put in is reflected by the result, they definitely are **my** favourite maps of this year.
'Supply Depot, by ginc'
'Frostbite, by Moonkey'