It's 2010. Hopefully by now you have beaten 1985's Super Mario Bros. If not, please get off my lawn and go away. If you have, continue onward to spoilers!
In 1986, a special, limited-edition version of Super Mario Bros. was given away by Japanese radio program All Night Nippon. The game is a hybrid of the original Super Mario Bros. engine, Famicom disk game Super Mario Bros.: The Lost Levels and the celebrity personalities of All Night Nippon.
When you beat Super Mario Bros., you get this ending:
But when you beat the All Night Nippon version, you get this poem:
"Peace is paved
With kingdom saved
Hurrah to Mario
Our only hero
This ends your trip
Of a long friendship"
And then this screen.
The All Night Nippon ending is way better than the abrupt Super Mario Bros. ending. Way better.