The Arthur Games
Sometime back in the 1980's I fell in love with a game called Ghosts 'n Goblins, which featured a knight called Arthur as the hero. I had a pirated copy for my Commodore C64. I played it over and over, and even managed to finish it without cheating.
Then when I started collecting computers back in 2002, I decided to get me an original copy of Ghosts 'n Goblins for the C64. After a while I stumbled over the same game again, but this time for the Sinclair ZX Spectrum 48K.
It got me thinking. I had a bunch of old computers and consoles. Maybe there existed a port of Ghosts 'n Goblins for some of them. It sure did. And there was a sequel to Ghosts 'n Goblins called Ghouls 'n Ghosts so now I knew what I had to do.
Now I'm now actively collecting all games featuring Arthur as the hero for all platforms they were ever made.