I had to go with Super Mario World for these reasons: Art Style, GREAT SOUNDTRACK, lots of content and challenge. Great as Sonic was, it felt a bit too much on the easy side for my taste, specially if you could always pick a ring to stay alive. Also, I never liked the original soundtrack, specially with the so many great ones Sega had given us up to that time (i.e., Shinobi and others). But I loved Sonic too.

Sonic The Hedgehog! I had a Genesis over an SNES, so that probably helped my decision. It is, after all, the first game I ever played.

I'm the only one who said Sonic?

Your are one of 7 people according to the poll X)

Super Mario World. I never liked the Sonic games because other than a few stages, it felt more like turn into a ball as you start going and hit jump every once in awhile. The stage itself will take you where you need to go without any player input. Basically. Sonic the Hedgehog has always felt way too automated to me. Never been a fan of any of them except for 3D Blast. Adventure and Adventure 2 are garbage pos too.

My choice was and will always be Sonic. Its the superior game and alot more fun in my view. Be it graphics, music or gameplay.
Of course, its not to say Super Mario World wasnt a good game, because it was, but 2D Sonic was always better in my opinion. Unfortunely 3D poped in after that and all went down the crapper.

As a fan of both Sonic and Mario, Super Mario World is sublime, and was never approached in excellence by any 2D Mario until NSMB for Wii U (sadly not getting the love that earlier NSMBs got, because it beats the shit out of the Wii and DS games), which only gets where it is by emulating World's formula, although still not quite (for while NSMBU re-introduced a dynamic world map and secret paths between worlds more complex than a mere cannon shot, it still does not match the intricacies of World)

Sonic the Hedgehog is not the pinnacle of its own formula, which was reached with Sonic 3 & Knuckles, where the 2D Sonic formula was made sublime in a way that has not been matched save perhaps by Sonic Advance 1.

This one is easily Super Mario World for me. Sonic is good, but it doesn't even compare to Super Mario World to me. I can play Super Mario World levels many times without getting bored of it. Can't exactly say the same about Sonic.

Do we really need to use the spoiler tag with 20+ years old games? I won't use it.

I was a SEGA follower (I don't like the fanboy term) back then and it obviously affects choice, which is Sonic.

I agree that Mario World is a better game, but after playing both games (a friend of mine had the SNES and the game) I had more fun with Sonic than with Mario for a variety of reasons: the urge to collect the rings to be safe against eneimes and get extra lives, the PCs with power ups like the shield, the different music styles, the animals that run free when you killed their mechanical trap... yep, I liked Sonic more than Mario.

Super Mario World was 2D Platforming Perfected IMO. Amazing game.