You might have already heard of The Percy Jackson and the Olympians series. It's more a spin on mythology than actual paganism, but I appreciated the themes of young people who don't fit in, and I think Percy Jackson was the perfect narrator because (spoilers!) there are so many opportunities for the story to not be about him even though it's from his point of view.
I'm not a fan of the Heroes of Olympus series because there are too many new characters that are all in first person tense, it gives me a headache.
However, I think the Heroes of Olympus series is a good jumping-off point for pagans to discuss Soft Polytheism and Syncretism, which can be controversial but also safe if a fiction is offered as a hypothesis.
I'll think of more.
I loved The Mists of Avalon, but I found out some horrible things about the author so I don't know about recommending that book anymore. :-(