As a follow-up to this post, I recently heard @Cam Banks list Pendragon as his favorite RPG of all time, so it's definitely possible that Prince Valiant's influence can be felt in games you like, such as Marvel Heroic Roleplaying and the Cortex system.A little bit off-topic but related: there are some games which seem like they should have had a big impact/influence but seem not to have.
One from the late 80s is Prince Valiant. One from the late 90s is Maelstrom Storytelling.
These make me think of two questions:
(1) Why does the impact not happen that seems like it should have done;
(2) What are the current games that aren't having the impact/influence that they should? (This one is a bit harder of course from our current vantage point!)