Just watched this at the Sundance Film Festival. Absolutely great film. Dark, smart comedy in the spirit of Rushmore. The Bobcat is BACK! Very good cast; great soundtrack. He uses very real issues to simply tell a story about the relationship between an ungrateful punk kid and a painfully weak father. In the Q&A after the film, Bobcat pointed out that most of the comedies being made these days are basically R-rated films made for 13-year-olds (mindless, raunchy, etc.). World's Greatest Dad is a comedy for adults: insightful, original, uncomfortable at times...hilarious. Robin Williams manages to be miserable, mean, touching, and funny without any conflict at all, an inspired break from his traditional roles.