One of my all-time favorite games is Super Mario World. I can't believe that game is over 20 years old (released in the US in 1991). I know all the tricks in that game and have beaten the game at least several dozen times. I downloaded it on Wii as I have misplaced my original copy.
Some of the tricks I know are ditching a Yoshi to keep Mario from falling in a hole and pushing Start/Select to back out of a level to avoid losing a life (provided that you have already cleared the level). You can also replay a castle or fortress if you push the L and R buttons simultaneously while on the map screen.
Some of my other favorites are Super Mario All Stars an Donkey Kong Country 1, 2, and 3.
I wish I still lived in Iowa; Everything there from rent and groceries to Cable TV is much cheaper in Iowa (especially with an overbuilder in town).