1. Animal Crossing (GameCube, 2002)
Whereas most of the games on this list halfheartedly touch on holiday themes, the first Animal Crossing absolutely buries you in gift-giving cheer. It uses the GameCube's internal clock to "know" the exact date down to the second - so, once winter rolls around, snow starts to fall, lights appear in trees and special "Christmas Remix" editions of the in-game music take over. Even the lovable townsfolk get into the act.