Super Mario Bros. 3, fascinating Level Design, it felt completely different from the other 2 Super Mario Bros. games.
Only if it could save your progress, it would have been the best Side Scrolling Mario Platformer ever created.
Yoshi's Island, because of the adorable Art style, and the enemies look cute.
The difficulty Level is just right, it's easy to play and easy to understand, and it includes hard Levels, and yet they've found a great balance between easy and hard.