Ah man, SOOO many to go with...
1: SEGA skipping 32X in favor of a standalone SVP cartridge for Genesis/MegaDrive
2: NEC & Hudson actually redesigning Tetsujin into a capable 3D/2D console with that MJPEG decoding feature instead of the lukewarm PC-FX that actually launched
3: SEGA not rushing Saturn's Western release by several months
4: SEGA not cancelling Saturn versions of Streets of Rage or Eternal Champions
5: FM Towns Marty 2 being an actual spec revision
6: CD32 American shipments not getting held up in customs so Commodore doesn't go bankrupt
7: SEGA maybe actually taking the M2 or the GPU that'd eventually go into Gamecube, delay Dreamcast by a year, add in DVD-ROM support and give Saturn a final year's-worth push
8: Ken Kutaragi never leaves PlayStation
9: Sony never moves PlayStation's headquarters to California
10: Nintendo adds DVD-ROM support to Gamecube as standard
11: Satoru Iwata never passes away
12: Kenji Eno never passes away
13: Akira Toriyama never passes away
14: Microsoft never promotes Phil Spencer to head Xbox. If unable to find a better replacement, then just spin off/sell the Xbox division to an outside company in 2014 like they wanted (or shut it down)
15: Fortnite and PUBG never became popular
16: GTAV never became a massive seller
17: Minecraft never became popular
18: Arcades (REAL arcades) never died off
19: SNK made more realistic specs for Neo Star and released it instead of Neo Geo CD
20: NEC & Hudson made more substantial upgrades to SuperGraphX
21: Atari never cancelled the Panther, and delayed Jaguar by 3 years (so 1996 launch) for better hardware and better software support
A timeline where the Saturn took the PS1's place as the lead 32-bit platform.
Considering what PlayStation's become today? 1,000,000% agreed!