Henry of Skalitz (Kingdom Come: Deliverance) vs Ser Arthur Dayne (Game of Thrones)
Ser Arthur Dayne's incarnation also features his appearances in ASOIAF, but it wouldn't fit in the title.
Also "DUDE YOU KNOW HENRY LEARNED REAL TECHNIQUES", yes, I know, but what is decent in our world might not be decent in theirs, taking 2 master swordsmen from their own respective worlds and seeing how they stack up instead of saying that one knows proper techniques for our world and the other doesn't is just stupid.
Anyway.
Henry:
Arthur Dayne:
Who wins?