I haven't said my favorite Mario game.
Super Mario Galaxy was good because of the music and storyline and, of course,
//www.tamatalk.com/IB/applications/core/interface/js/spacer.png. Very nice in my opinoun.
Bad things, Player 2 was kinda useless.
Super Mario Galaxy 2 was good because of as said before the music and eaiser gameplay than the first one. Plus you get to play as Luigi whenever you want(after you beat Bowser, but he'll appear in some galaxies with the option to play as him even if you haven't beat Bowser yet) without exiting your file and changing the settings. The Green Star Challenge was fun, and so was Fluzzard's minigames. But I hate hate HATE the Chimp. >
The game is also good because Player 2 had more options than the first one.
New Super Mario Bros. Wii was fun cause of the MultiPlayer option(not a good game with 4 peoples, but tis a fun game), the power-ups, the Koopalings(absent since Super Mario Bros. 3), Spin Jump(absent since Super Mario World), picking up your buddies and tossing them to their doom(epic), a strong Ground Pound that can defeat most enemies that are only on the ground, and that you can ride the Koopa Clown Car!! 8D
New Super Mario Bros.(DS) This was okay, I loved the shell power-up. The shell can kill most enemies/bosses that are hard or not possible to kill. >:3 Plus the option to be Luigi.(SPOILERS IF YOU HAVEN'T COMPLETED THE GAME YET)
Yeah, I haven't listed all the games cause I played the first 5(Super Mario Bros. 1, 2, 3, Super Mario World, Super Mario 64) when I was young, so I can't really tell why I like the game. The Mario games I haven't played yet:
Super Mario Sunshine
Super Mario 3D Land(it's for the Nintendo 3DS, it isn't out yet)
And, yeah that's it.
EDIT: Still haven't said my favorite game yet. <.<
My favorite is either Galaxy 1 or 2. Maybe both.