AD&D: Cloudy Mountain 21
Baldur's Gate 20
Baldur's Gate II 20
Baldur's Gate: Dark Alliance Series 20
Chronicles of Mystara 20
Dungeons & Dragons Online 20
Eye of the Beholder Series 20
Gold Box: Pool of Radiance Series 20
Gold Box: Dragonlance Series 20
Gold Box: Savage Frontier Series 20
Gold Box: Spelljammer 20
Icewind Dale 18
Icewind Dale II 20
Neverwinter Nights 20
Neverwinter Nights II 20
Planescape: Torment 21 - Still may be the best story a video game has ever told. Certainly the best written.
Silver Box: Dragonlance Series 20
SSI Dark Sun Series 20
Sword Coast Legends 18 - Uninspired, broken, and bears no real resemblance to 5e other than the proficiency bonus system. It failed for very valid reasons.
Temple of Elemental Evil 20
Warriors of the Eternal Sun 20