- Sonic the Hedgehog (Master System). Not including Super Mario Bros 3 here, as I replay the All Stars version on SNES, not the NES version.
- Yoshi's Island (SNES)
- Tomb Raider II (PS1 / PC - although I've now moved on to the remastered version from 2024)
- Resident Evil 4 (GameCube)
- Super Mario Galaxy (Wii)
- Resident Evil 2 Remake (PS4)

Haven't really replayed anything from current gen.

Not sure how multiplayer games or things like Roguelikes play into this. 

NES Gen- Mega Man 2

SNES- Kirby Superstar

N64 Gen- Probably Mario 64. Maybe Pokemon Red/Blue?

Gamecube Gen- Nothing comes to mind actually. I think this is the gen where pick up and play games were really not favored and there are not a lot of games that lent themselves to lots of replays. Probably Resident Evil 4 since I at least played that enough to unlock all of the super weapons and such. Although most of those replays were probably on the Wii version. Played through KH2 a few times although not all on PS2.

Wii Gen- Super Mario Galaxy 2 or maybe Mass Effect 2.

Wii U Gen- Yeah I'm calling it Wii U gen cause that's what I played most. Anyway Kid Icarus Uprising.

Switch Gen- Probably slay the spire if you're counting roguelikes. If not, maybe Spiderman on PS4? I played that like twice.

Gen NES = Ducktales
Gen SNES = StreetFighter2 (Turbo/New Challengers)
Gen N64/PS1 = Mario Kart64
Gen GC/PS2 = Final Fantasy10
Gen Wii/Xbox/PS3 = God of War3
Gen Switch/PS4 = LoZ Breath of the Wild
Gen Switch2 = LoZ Breath of the Wild SW2 Edition

NES - Double Dragon 2, Turtles 2, Megaman 2, Super Mario Bros 3
N64 - F-Zero X, ISS 98
Xbox - Ninja Gaiden
Wii - None
Switch - Street of Rages 4
Switch 2 - MP4 and Starfox. In the end it will be Starfox.

Gen 2 - Adventure
Gen 3 - The Legend of Zelda
Gen 4 - Golden Axe

Gen 5 - Final Fantasy 7
Gen 6 - Final Fantasy X
Gen 7 - Dark Souls
Gen 8 - Super Mario Maker

Switch - Puyo Puyo Tetris
Switch 2 - Just got.  Only been playing the FF7 R games so far.

Gen 2 - Galaga
Gen 3 - Sid Meier's Pirates!
Gen 4 - Panzer General
Gen 5 - Steel Panthers I/II and Age of Empires 1/2
Gen 6 - Combat Mission: Barbarossa to Berlin
Gen 7 - Portal 1/2 and Grand Slam Tennis
Gen 8 - Kerbal Space Program
Gen 9 - Too early to tell

Gen 3: Mega Man 2
Gen 4: Mega Man X
Gen 5: Goldeneye 64
Gen 6: GTA 3
Gen 7: GTA 4
Gen 8: The Binding of Isaac
Gen 9: The Binding of Isaac

I dont replay many games nowadays got to many to play new but.

Ps1: diablo prob dozens and dozens of times, ff7 at least 15 to 20x and ff9 about 4 times when i was a kid(played ff7,8,9 last till this year.
Ps2: ffx dozens of times, baldurs gate dark alliance. Devil may cry,timesplitters2.
Ps3:uncharted1
Ps4:nothing
Ps5:nothing

Gen 3: Castlevania
Gen 4: Mega Man X
Gen 5: Star Fox 64
Gen 6: WarioWare, Inc.: Mega Microgame$!
Gen 7: Rhythm Heaven Fever
Gen 8: Deltarune
Gen 9: MINDWAVE (when it comes out, I already put 50+ hours in the demo which is not normal for a sane person)
PC: Overwatch

Depends on what you count as replaying and does emulation count. And I'm not even trying to include PC games.
But here's major alternatives:

Gen 2 - Campaign '84 (Colecovision)
Gen 3 - Snail Maze, Hang-On, Slap Shot, Rampage, Asterix, Tennis Ace, Populous, Phantasy Star (Master System)
Gen 4 - Phantasy Star II/III/IV (MD/Gen)
Gen 5 - Ridge Racer Type 4 (PS1)
Gen 6 - Tekken 5, Robot Warlords, Okami (PS2)
Gen 7 - FlatOut: Head On, Phantasy Star Portable (PSP)