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?
Portal 2, with the steam workshop on PC it’s never over. Quite satisfying to find solutions after spending a while on a map.