SMB1 references in other games
"Super Mario Maker" - This Wii-U game allows you to make your own Super Mario Bros. levels, along with New Super Mario Bros., SMB3 and Super Mario World levels! What's more is you can actually PLAY the levels you created and share them via the internet (for now, anyway.)
"WarioWare: Touched!" - in 9-Volt and 18-Volt's Retro Action games, there is a self-titled minigame based on Super Mario Bros. Also, touch the baddies to make them disappear in another microgame.
"Warioware: Twisted!" - classic SMB-style levels are bent into roundness navigable only by rotating.
"WarioWare Inc.: Mega Microgame$" - 'Super Mario Bros.' In this microgame with familiar graphics, stomp on goombas.
Check out the end part of World 2-3 for "Super Mario 3D Land." The classic stairs along with classic graphics to accompany it.