Super Mario Bros. VS Dragon Ball! The most famous video game hero takes on one of the best known anime protagonists!
DMUA: Yeah... When you think about it, it's super close. Mario survived the explosion of his universe, but Goku shook it as a Super Saiyan God. Personally... I'd side with Goku. Firstly, the Dragon Ball universe 7 is 2.7 times bigger than ours. That easily makes Super Saiyan God Super Saiyan Macroversal. So, Goku could easily hurt Mario, especially considering the Kaio-Ken. Then, there's speed. Mario is easily MFTL with scaling to Bowser, and Goku is also MFTL with scaling to Beerus. Again, with the Kaio-ken, Goku could outpace him. Then, arsenal. Mario has several power ups. Some of the most notable being the usual shrooms and stars, which I only see delaying the inevitable.
Note: This is much closer than many would think.