I can't help on all of them but...
Playstation 1 (US Releases)
-Check out Game Rave, the best resource you will ever have:
http://game-rave.com/?page_id=167
Sega CD (US Releases)
-172 distinct variant releases. This is from my custom spreadsheet.
Sega Saturn (US Releases)
-256, Satakore has a phenomenal database that I consider the best:
http://www.satakore.com/saturndb.php...d=%C2%A0Search
3DO (US releases)
-Check out an insane asylum. Seriously though, 3D0?!
If you are just starting to collect for any of these individual ones though you and your wallet are going to be in a world of hurt. Everything is stupid expensive now.