Minigames, regardless of it being distracting, nostalgic, or worldbuilding in intent, are great methods of providing variety. It's a shame that they are so often overlooked by both players and developers because they are indicators of quality and effort, so this thread is for the purpose of recognizing them.
Anyways, while I do appreciate things like Wolfenstone 3-D in
Wolfenstein II, the arcade and Atari parody games in Fallout 4, or a couple of Timesplitters 2 levels in Homefront: The Revolution, these are novelties that merely cause memories of a better time to surface. My personal favorite minigame is Caravan from Fallout: New Vegas. For those who do not know, it is a card game completely unique to the game. It's non-essential, but unlike the minigames in its sequel, Caravan is integrated into the world. The game is played with NPCs, each of which have their own skill level, and there are consequences of winning and losing in the main game. In one of my New Vegas playthroughs, I roleplayed as a gambler who would play until either my opponent or I was broke, which was some of the most fun I've had in a video game.