This is super nerdy but I think the PJO series could make an amazing version of Dungeons & Dragons.
First off we call it Demigods & Drakons because it fits the D&D name and gets to the point.
It wouldn't be hard to set up. The rules have already been set up by numerous other games and would have to be minimally altered to fit the PJO world.
You still create your character
Race (Saytr, Human, Nymph, etc)
Use a D&D system to generate stats
You then choose a godly parent (Roman or Greek) and get a stat benefit based on your choice
Mars/Ares get boost to strength and toughness
Athena/Bellona get increased inteligence
Apollo gets increased healing
You choose a specialization, something similar to a class, based off your parent
Apollo kids can be bards or healers
Hermes kids can be thieves
Some specializations would be available to anyone
sorcerers to control the mist
any female could be a Hunter of Artemis
Basically you'd go around on quests and exploring and would do what demigods to best, try and keep from getting yourself killed by a giant horrible monster.