I think this video should solve all the Sound Quality of voices/music and graphical features of Genesis/MegaDrive vs. the SNES.
(the 32x is an addon to the Genesis/MegaDrive but is still considered part of the Genesis)
No offense Gary but the 32X is overrated. It would have been good if it had more games but it died off quickly and the selection of games it had were very few. Also number of good games such as Virtua Hamster never made it onto the market. Others such as Doom 32X were released incomplete. (Doom 32X was missing about half of the levels in the original version because of the fact it was rushed to meet the holiday season.) Also there weren't any good 32X CD games so it was kind of pointless.
The Sega CD is severely underrated on the other hand because it was capable of CD Quality Audio and just made things look better. Plus it had a little ability to imitate the SNES's Mode 7. (see Sonic CD's Special Stages for details.)
The only problem with the Sega CD was the lack of good titles. There were some and these ones are probably my favorites:
-Eternal Champions: Challenge From the Dark Side
-Both Ecco games as they are nearly the same as their Genesis counterparts. (the soundtracks were ruined by Spencer Nielson. I was hoping for CD Quality remixes of the Genesis Chiptunes from the Genesis versions. Instead I ended up with some Underwater ambeint sound type music, which sounds good but not spectacular.)
-Sega CD Jurassic Park. Its a nice little game but most people are mixed about it from what I've seen.
-Sonic CD (of course.)
-Earthworm Jim: Special Edition (Has CD Quality audio remixes of all the tracks from the game which are composed by Tommy Tallarico. It also adds a new level called Big Bruty and some new items to the game. It even has the Intestinal Distress level that was in the Genesis version but not the SNES version due to cartridge space limitations due to the buffing up of graphic and sound quality. Also was released for Windows 95.)
-Wild Woody ( Okay, this game is actually a mockery among many. People say the game has one of the worst names ever. The game is generally seen as a collector's item. It was the last North American Sega CD game ever released. It ended up leaving Sega only to wind up in bargain bins. The game itself is actually pretty decent. The controls might be a bit confusing at first but eventually it seems like a really great game. If that's not enough, the soundtrack was composed by none other than the Heavy Metal Artist, Bumblefoot who is called Ron Thal in the credits. I've been to the programmer's website. He also programmed Sega CD Jurassic Park ironically. He doesn't really enjoy hearing the jokes made about this game since he worked hard on it while programming.)