I played through Roberta Williams' "Mystery House" (1980) the first time this year... only played the King's Quest games and Phantasmagoria of her in the past.

I also played through "Holiday Maker" (1989), "Bill & Ted's Excellent Adventure" (1990), "Adventures of Willy Beamish" (1992), "Leather Goddesses of Phobos 2" (1992), "Igor: Objective Uikokahonia" (1995), "Hollywood Monsters" (1997) and "Blade Runner" (1998) this year.

WoW, Starcraft, AoE II to name a few.

Trying to stave off starvation. Everyone's favorite game since forever.

But really, cool question. I think it was Gothic 2 from 2002.

Well, I think Castlevania (1987?) takes the cake, but I only played it for about 30 minutes. I was trying to get my little girl into some REAL games. ;)
I put some serious hours (maybe 5) into Final Fantasy VIII (1998) and also did an N64 potpourri back at the beginning of the year while I was waiting for Breath of the Wild to come out.

Picked up a snes a few months ago so probably Mario world

Donkey Kong (1982). 100,000 points, I will reach you someday...

Seems like 89 is the year to be this year for me.

I’ve played:

Cobra Triangle
The Battle of Olympus
Truxton

All came out in 1989.

Star Fox and Metroid Zero Mission were the oldest i actually completely played through.

Fire emblem genealogy of the holy war

Day of the Tentacle Remastered. I know it's a remaster, but the actual game is from 1993 so I think it still counts =P