The only criteria I chose for this list is that all of my picks must have been designed with a computer system in mind as the primary platform, or be PC-exclusive. That means no console up-ports or simultaneous multi-platform releases! Oh, and they have to still be fun to play today, too.
As ever, keep in mind that this are my personal picks and no-one else's.
HM. AM2R (Some awesome fans, 2016)
50. D/Generation (Robert Cook, 1991)
49. Jazz Jackrabbit 2 (Epic MegaGames, 1998)
persists to this day) and support for custom-made levels, giving it quite a bit of replayability. A solid exclusive title for PC proponents and still a fun platformer to this day.
48. Oregon Trail Classic (MECC, 1990)
47. MegaRace (Cryo Interactive, 1993)
46. The Incredible Toon Machine (aka Sid and Al's Incredible Toons) (Jeff Tunnell Productions, 1993)
The Incredible Machine series was a prominent one in the 90s, spawning so many spinoffs, re-releases and expansion packs that it was a bit absurd. My favorite of the series is this one, taking the same concept and adding in two Itchy and Scratchy-esque characters (Sidney Mouse and Al E. Cat, voiced by Rob Paulsen and Jim Cummings respectively) who were constantly at ends with one another. So in many puzzles, your goal was to help one defeat the other with a variety of tricks and traps - fire-breathing dragons, catapults, falling anvils and pianos, pushpins, seesaws and pistols just to name a few. The high-quality animation, hilarious voiceover and a great twist on an already creative concept made it one to remember, and of course, once you beat all the included puzzles, you could go ahead and build your own to continue the chaos.
45. Shadowgate (Zojoi, 2014)
44. Team Fortress 2 (Valve Software, 2007)
43. Are You Afraid of the Dark?: The Tale of Orpheo's Curse (Viacom New Media, 1994)
42. Epic Pinball (Digital Extremes, 1993)
41. Lemmings (DMA Design, 1991)