Basically asking which game would you keep playing regardless on how many years passes, you always play that game every year (doesn’t matter how much time).
In my case that game would be Risk of Rain 2. Each year me and friends play some runs and have a lot of fun since it was on early access (we always play a few months every year)
Which game will you keep playing?
Skyrim. "Wide as an ocean, deep as a puddle” don’t care. I play it every winter and it just feels like a cozy escape. Mods make this game have unlimited replay value and there are surprisingly in depth builds you can make. I have sunk thousands of hours over the years and still haven’t beaten the main quest.