Bros 3 is my favorite. Yoshi's Island is the runner-up., 64, Sunshine, and Galaxy are also great games. SMW is good, but I don't consider it the best for reasons I've already explained in other topics. --- Word to your mother.
Most of this board will pick the first one they played. Nothing inherently wrong with that. --- Check out my sound cloud! I write orchestra pieces, sometimes piano solos: https://soundcloud.com/soaringdive