The Grand Tour

[Senkusha]

This is a fan-fiction about Ryoga (from Ranma 1/2), and is quite interesting as Ryoga gets lost throughout many fictions (galaxies included) Here's a list of this mega crossover fictions:

• Star Trek Deep Space Nine
• Star Trek Voyager
• Ranma 1/2
• Star Wars
• Magical Girl Lyrical Nanoha
• Sailor Moon
• Avatar: The Last Airbender
• Slayers
• DragonBall

The Grand Tour

A crossover fic. Ryoga's curse of 'lost' threatens the fabric of the multiverse itself. The USS Voyager is swept up in his wake of chaos. The TSAB steps in to clean up the mess, recruiting Ranma to aid them, but it may already be too late to catch him...

I'm sure I missed a few of the series! 21 chapters in all, and the story was completed in 2009.

Update: At the end of the story, DrunkenGrognard, kindly provided a list of all the sources: