Easy Mario games wins. How do I know? I'll show you:

This is what is considered the most ambitious Mario Game of all time and look what we got

http://www.metacritic.com/game/wii/super-mario-galaxy

And this was suppose to be the most ambitious Sonic game of the time and look what we got:

http://www.metacritic.com/game/xbox-360/sonic-the-hedgehog

I rest my case ;)

It's debatable.

But Sonic is better than Mario.

https://www.youtube.com/watch?v=3aq_dOLFmxA

Genesis Does! What Nintendon't.

https://www.youtube.com/watch?v=k7nsBoqJ6s8

What?! I need to set things straight here, Mario is so much better, along with the Super Nintendo >>> Genesis.
So there.

I always liked Mario better, the older Sonic games have an almost "arcade like" feel that get's old quickly, meanwhile a game like Super Mario Bros. 3 or Super Mario World I could play all day long.

Of course, if you're gonna compare the new Sonic to Mario, Mario will always win. :P
Nintendo doesn't rape Mario, they actually try to make a decent game.

Now, if you try to make old-school Sonic vs old-school Mario, be prepared to flame wars. xD

The correct answer is Jazz Jackrabbit, suckers.

An Goomba saying this...suspicious.

Metroid :D

Mario is a monster. He has, and continues to this day, to commit genocide against my people.

In stark contract, Sonic is a liberator of small animals trapped in mecha suits programmed for evil. Bonk!

SONIC IS A METH HEAD! :P

MARIO IS A PERVERT! ( ಠ◡ಠ )

Mario without a doubt. Sonic is annoying as hell and his games suck.

I've always preferred Mario games to Sonic games.

SONIC AND MARIO ARE VIOLENT!