Well, it was Legend of Zelda; but after that last Mario movie, Nintendo is actually making one. So then it was Dark Souls, but they are making a movie of that too!

Though I have major doubts about either being anywhere close to what I imagine they could be.

All I have left is the Neuromancer series and Beyond the Mountains of Madness. Both have attempts at a film adaptation but either they were straight up killed or are stuck in production hell.

Anything else is entirely made up in my own head, so will likely never get made unless I come into a lotta money before I die.