Check my Completionist [completionist.me] for a list of games.

Aiming 100%:

Some (or lots of) achievements left
Balatro
Baldur's Gate 3
Borderlands The Pre-Sequel
Company of Heroes 2
Death Stranding Director's Cut
Deep Rock Galactic
Devil May Cry 5
Dishonored
Dying Light 2
Embr
Garry's Mod
Midnight Ghost Hunt
Monster Hunter: World
PAYDAY 2
PC Building Simulator
Planet Zoo
Red Dead Redemption II
Resident Evil 0
Terraria
They Bleed Pixels
Transistor

Regulars (always new achievements being added):
Killing Floor 2
SMITE

Impossibles/broken achievements:
MIND SHIFT (levels and achievements broken)
Pinball FX2 (Removed from the store along with all DLCs)
Team Fortress 2 (youtube achievements not working)

Need Multiplayer:
Grand Theft Auto V
Plague Inc: Evolved
Transformice