Fallout
Fallout can easily be played out of order. Even though each game builds upon the last by showing how different parts of America were affected by the apocalypse, playing Fallout 4 before Fallout, Fallout 2, or another of the other Fallouts will never mess up your understanding of the series in general.
This example is unique in the way that the reason the Fallout games can be played out of order is that they have their own self-contained stories. There are definitely some clever references to past games that will land ineffectively on newcomers, but each game is playable alone. The gameplay mechanics and presentation undoubtedly improve over time, but each game’s strengths are surprisingly different from the others’.
Ultimately, go ahead and play in whichever order you want. Just try not to set the world on fire.
