SNES platforms:
First, getting the obvious out of the way: Super Mario World, Super Mario All Stars, Yoshi's Island, Donkey Kong Country 1 2 3, Super Metroid, assorted Megaman games - I didnt like Megaman and Metroid much, Yoshi was a bit slow but otherwise impressive, DCK is mainly for the good looks and sound, Mario rocked in its bareboneness.
Puzzle oriented: Prince of Persia 1 and 2, Blackthorne, Flashback, Out of this world, Lost Vikings 1 and 2 - niche games, I havent played them much (or at least not the SNES versions) and cant swear on their quality, but some might be good.
Some combat platformers:
Castlevania IV - good
Demon's Crest - good G&G spinoff, slower pace due the adventure spin
Super Ghouls and Ghost - good
Contra - good
Sky Blazer - little known but nice.
Hagane - played little but seemed pretty good
Earthworm Jim 1 and 2 - pretty amusing looking and playable, at times dull, IIRC.
Joe and Mac 1 and 2 - played little and long ago, should be ok
Magic Sword - more combat than platformer, ok to kill a little time
Ninja Gaiden Trilogy - for the NES lovers
Kirby - assuming there is some good one
Aladdin - and a ton of other Disney games, if they are your thing
Cybernator - someone loves it, never played much myself
Go Go Ackman - from a manga of Torayama, 3 platform games were made on the SNES, jap only. Gameplay was nothing special but looked amusingly absurd, especially the latest ones.
Super Turrican 1 and 2 - played briefly, seemed good, epecially 2
Super Valis 4 - mediocre
Pitfall Mayan Adventure - nothing special but neither too hideous
Super Bonk - played briefly, looked good. IIRC it also has a jap-only sequel or two, fan translated.
Tiny Toons Adventures - I guess is ok, if you like cuteness
Cyborg 009, assorted James Pond, - no idea if are good, played too briefly
Rocket Knight was avail for both MD and SNES, and I think the games were different. On the SNES was called.... Sparkster maybe?
SNES fighting games:
From Capcom there were Captain Commando, King of Dragons, Knights of the Round, assorted Final Fight games, and probably more. KoD looked relatively good, but Final Fight is probably still the best.
Sonic Blastman was another game I cant recall much of...
Teenage Mutant Ninja Turtles 4 was good IIRC
Ninja Warriors was different from the arcade, pretty good, but 2d movement, in other words you could move left and right, not up and down as in FF and clones.
X Men Mutant Apocalypse - similiar to ninja warriors, briefly played, looked good
Megadrive:
I havent checked my list of games, but a few platformers are:
Contra Hard Cops - very good
Castlevania - not the best of them, but playable
Gunstar Heroes - Good
Rolling Thunder 2 and 3 - slow pace, but good in their own way
Wonderboy - cant remember whch were the good ones
Toki - arcade was nice, no idea of the conversion
Wardner - see Toki, but the arcade is really old in this case and looks dated
Revenge of Shinobi, Shinobi 3 - Good
Ex Ranza (maybe called Ranger X in the USA?) - really liked this one
Alien Soldier - from Treasure, too confusing for me to stick with it, but has some fans
Strider - decent
Sonic - Duh. More of them than I could count
Mickey Mouse and Donald Duck games, lots of them, cant remember the names but some were decent
Alex Kid, Rastan Saga - havent played but sound interesting
Mystic Defender - at the time I liked it. Now I cant ever remember what it was about =p
Splatterhouse 2 - at a glance looks good
Fighting games:
Golden Axe - good, I didnt like the sequels
Street of Rage 1 / 2 / 3 - someone loved them, I preferred Final Fight
Splatterhouse 3 - see sphouse 2
Alien ... what was it? Alien Storm maybe? Was good for a genesis game.