Super Mario World is the only 2D Mario game that I really got into. I had a blast with SMB Wii, and I appreciate most of the other games (particularly 1-3), but SMW was the first video game that I ever completed, so it's an easy decision for me.

Super Mario World. One of my childhood games.

I also loved Super Mario All-Stars.

Super Mario World is the best.

SMB1, SMB3, and NSMB are great.

The rest of them just exist for me.

hands down Super Mario World

NSMB Wii ...it brought my fav 2D platform to new levels of fun by making it 4 players

Super Mario Bros. 3. Short levels, packed with ideas, tight controls, interesting power ups (sidenote : I feel SM3DW has a lot of what made SMB3 great).

As for a new entry: visual overhaul is imperative (the "new" look is old) and the hard part, spice up the gameplay while still being true to the roots of the series.

SMW followed by SMB3

Best: Super Mario World. Also the greatest of any Mario game.
Worst: Any Mario game with New in the title.

Rol goes through all the trouble to set up the poll, and then some clown spits on that work by picking New Super Mario Bros. 2. Some people have zero shame...

Anyways, I voted for SMB3, for the many reasons already shared. My runner ups were the console New SMB games, both of which were pretty good. I actually liked New Super Luigi U as well, but it felt too different to really make the Top 5. Still better than the handheld games, though.

Super Mario World. I mostly played it on GBA as Super Mario Advance 2. GBA was my first handheld.

Bonus: Whatever it is, I don't want another New Super Mario Bros. They're too stale now.