I feel particularly well placed to vote in this poll as I played five 2d Mario games (each for the first time!!) in 2009:

Super Mario Bros
Super Mario Bros 2
Super Mario Bros 3
New Super Mario Bros
New Super Mario Bros Wii

I enjoyed New Super Mario Bros Wii the most, but it's pretty close between that and World, which I played a year earlier.

When the poll will end, I'll declare the best Mario game! New Super Mario Bros Wii is ahead, Super Mario World close! NSMB = Epic Fail XD

NSMB DS Was a pretty low tied. Game. It wasn't amzing nore was it fun. It was just avarage. Though the sequal is amazing. Though I think its a tie for mario world and NSMBW. Though I picked mario world because I'm biased

Super Mario Bros. 3 is still the KING!!

Was my first game!! *sight*

I still love my SMB 3!

Super Mario Bros. 3! Best 2D Mario by far!

This is hard, I went with 3, but it's really hard. the first games are great but the controls got a lot better on 3 and onwards.

Sad to see no votes for the DS game, I loved it, actually think it's pretty close to the 3/W/Wii, but since it's so easy to compare to Wii it has a hard time getting votes. The fact that it has no Flying powerup makes it unique among the newer games, and I rally liked that.

They're all fantastic, but definitely Super Mario World.

NSMB DS was a nice little game, i've beat it 3 times and counting and i imagaine it will be a mainstay in my DS rotation, but the greatest mario game ever it is not. It really feels more like a reimagaining of the first super mario bros to me, like hey if we'd had the tech and experance 20 plus years ago THIS is what we would have made.

OT: SMW FTW, this game still looks just as good as it did when i was 12, and i still drag out the snes to rock it every now and again.

Super Mario World and it's not even close, lol.