Listopia > Adult Book Lists. Best "Strong Female" Fantasy Novels. 3, books — 18, voters Best M/F Erotic Romance like Fifty Shades of Grey (not paranormal, high school, gay or sci-fi) 3, books — 10, voters Best Series. 3, books — 9, voters Best ADULT Urban Fantasy, Fantasy and Paranormal Romance. New Adult New Adult fiction bridges the gap between Young Adult and Adult genres. It typically features protagonists between the ages of 18 and 25 with the cap at 30ish.