Castlevania Symphony of the Night, Lament of Innocence, Curse of Darkness.
The Final Fantasy series. Got 100+ hour games on memory cards on most of them. Some cartridges too.
The original Legend of Zelda. I still bust it out and blow through it from time to time. 25 years under my belt on that one lol.
That covers consoles.
When it comes down to PC games I've spent far too many hours on Diablo 2 as well. What takes the cake on PC games for me though would be good old Ultima Online. Pretty much the grand daddy of Mmos. I know for a fact I've spent at least a good 1000+ hours there.