Do you want straight
retellings of mythology, or things based on/inspired by mythologies?
Because if the latter, I wholeheartedly reccomend the Percy Jackson
series, about modern day children of the greek gods. It's fun YA stuff, no more (and by the end, no less) mature than Harry Potter. Its followup
series, The Heroes of Olympus
definitely goes a bit farther in that regard, as does his currently ongoing followups to that
, one revolving around the god Apollo, the other moving on to the Norse pantheon.
They're ten tons of fun, and downplay the, well ... Zeus-ness of Greek mythology without completely dumbing down everything.
And they're better than the movies. By, like, a lot