This is the best fanmade stuff anywhere IMO! For those who already don't know, it's basically a fanfiction animated story of Mario and Luigi meeting Sonic and Shadow. And the battles are taken to the level of DBZ. xD

I believe episode 7 is yet to come, but it is almost here.

Episode 1
Episode 2
Episode 3
Episode 4
Episode 5

Episode 6 (Part 1)
(Part 2)
(Part 3)

This is actually one of the few sprite video series that are actually interesting to watch.