This is a fun thread.
So I play games with my girlfriend a lot. Generally we kinda share who's playing what game so most of the list is the stuff we played together.
WiiU: Breath of the Wild
NES: Zelda 2, Castlevania, CV2, CV3, Metal Gear, Metal Gear 2: Snake's Revenge, Final Fantasy, Super Mario Bros 3
Turbo/PCE: Sonson 2, Lords of Thunder, Bonk's Adventure, Bonk's Revenge, Last Alert, Valis 2, Valis 3, Deep Blue, Dracula X
Genesis: Sonic, Sonic 2, Sonic 3, Sonic & Knuckles, Turtles Hyperstone Heist, Ristar, Bubsy 2, Castlevania Bloodlines
SNES: Zelda 3, Bubsy, Super Mario All Stars (all 4), Star Fox, Super Contra, Castlevania 4
32X: Knuckles Chaotix
Saturn: Sonic 3D Blast, Gex
Playstation: Final Fantasy 9, Symphony of the Night
N64: Star Fox 64
Dreamcast: Sonic Adventure, Sonic Adventure 2, Shenmue 2
PS2: MGS2, MGS3, MG2: Solid Snake
PS4: Sonic Mania, Sonic Forces, Bubsy, Street Fighter V
XBone: Cuphead
Arcade: Garou: Mark of the Wolves, CvS2
I wouldn't normally include a fighting game in a list like this but there were 3 neat victories. I got a full clear on Garou with Terry getting MIRACLE! ranking on every round. In Street Fighter V I beat Survival Mode on extreme, finally. I mostly cheesed the CPU with Rashid but at the end I had to work pretty hard. And finally my arcade just recently got a CvS2 setup so I played the computer to test it out. I beat Shin Akuma on one credit and was pretty happy about that. I used my patented team, P Groove Vega, Cammy, R2 Geese.
I played through 7 Castlevania games during October ending by beating Symphony of the Night the day before Halloween. Before Sonic Mania came out, my GF and I played through a good portion of the series. My favorite new game that I played was probably Sonic Mania. Second place would be Cup Head.
For next year? We're working our way through all of the Final Fantasy games and Metal Gear games. We've only got a few left in both franchises so we may finish those up. I'm hoping the Ys 8 translation patch comes out soon as I'd like to get back to that one. My girlfriend has never played any survival horror games, so I'm thinking we may try to tackle Resident Evil this October instead of Castlevania (we've done that twice now). The game I'm looking forward to playing the most, atm, is Romancing Saga 2 with it's recent release on PS4.