Is this it? asked The Strokes. The band may have struck that punctuation squiggle from the title of its debut album, but the post-Velvet Underground, post-Television, poster-boy-foxy rockers were, like the other artists who top our critics’ lists, definitely floating a query. Why is it that the year’s smartest, most accomplished, most ravishing entertainment tended to be consumed with quests and questions? At the cineplex, Peter Jackson’s adaptation of The Lord of the Rings illuminates the mythic searching of Frodo Baggins, while in Memento the hero’s noirish struggle to solve the basic mystery of life — Who am I? — makes for a thrilling existential interrogation. At home, a first-rate DVD revisits the biggest inquiry in all of cinema — What’s Rosebud? — while the greatest Internet thrill, a 2001 cyberspace odyssey, turned participants into scavenger hunters guessing where one Jeanine Salla was. The biography Savage Beauty probes the enigma of Edna St. Vincent Millay; The Corrections gives the American family the third degree; our critics wonder if any of it could be more sublime. (Meanwhile, they have a different line of questioning for the year’s foulest contributions: Have they no shame?) We know better than ever that life holds few certainties, but are sure of the resonant beauty of great work. This is it.