Fischer, if you count him as "modern"!
Notable King's Gambit Players?
Fischer, if you count him as "modern"!
Fischer didn't play the KG that often, though.

True, I don't know soo much about chess.
But Wikipedia suggest a handful of grandmasters including GM Joseph Gallagher, GM Hikaru Nakamura, GM Nigel Short, and GM Alexei Fedorov.
Which modern players play the King's Gambit consistently or with great success?
It can be IM's or GM's.