First game I ever played, and the best game to.
Almost all of my friends except for one have played this once in their life, some on GBA, and we all agree it's the best Mario game ever.
The only con is, it's a little on the hard side sometimes. Mainly with where the enemies and traps are placed. Other than that, it's fantastic.
The pros are: Good graphics for the time, Yoshi, great level desgin, classic gameplay, world map and shortcuts, the special zone (you'll see, probobly the radest and most tubular place in history, people who have played the game will get what I mean), just right difficulty, epicness.