The title says it all folks! If I had to choose, I would say 'Super Mario 3d Land', because it's one of my earlier Mario games I have played, and I honestly liked it the most. I have played the older games, but this was way after I got into Mario. If you don't mind, state your favorite Mario game :)
Super Mario 64 DS or New Super Mario Bros. I used to tweak on these games and try beat my original time xD
What I played, Super Paper Mario on the wii had a new level to it. Going 3D. Also Super Mario Bros. Wii was really great with the family.
Mario Party 1 because it turns your house into screaming, yelling, and plain out a hell-house after the first few turns! :D But in all honestly, almost everything you find in this Mario Party they took away in future Mario Parties. Bowser has became way dang to nice. Mario Party 3, him giving you items. Mario Party 2, like 5 coins will hurt me.(thank you Baby Bowser.) However almost all of the minigames are just plain out exciting. The original is always the best hands down. :) I also like Super Mario Bros, the original is always the best. Even though I beated it like 100 times already... :) I can go on and on about this, so I'll stop here. :)