I'll put it like this, RPG is by far my favorite Mario game just from it's uniqueness from the rest of the early series, Mario World was the most classic because everyone that had a Super had a copy of this and gettin through the Special Zone was like the goat accomplishment at the time, but Mario 3 to me was the most challenging game. Had a lot of great levels, and shyt I still ain't beat the final world that looks like hell.
I voted RPG tho only because no one else did, that game was crack.