Morrowind would be my choice, since there was almost a decade long gap between when i first wanted to play the game and when i actually played it. it didn’t reach my expectations but that doesnt matter that much to me since i still really liked that game. i didn’t finish it in my first playthrough, but i did once i got around to doing my second
Xonotic is one that i would reccomend heavily, and it’s an arena shooter