It's time for the year-end lists, and here's a fun one--the 2017 YouTube Ads Leaderboard, featuring the most-watched ads on the video platform this year. You'll recognize many of the spots, from Super Bowl commercials (Mr. Clean, Kia, Budweiser) to well-known celebrity spots (Natalie Portman for Miss Dior, Dwayne "The Rock" Johnson" for Apple). Remarkably,...