The Iron Giant - My favorite has to be this perfectly paced, brilliantly animated gem about the friendship between a boy and a misunderstood giant alien robot. Released in 1999, the movie is set in the late 1950s, a time of UFO hysteria and Cold War paranoia, and the film's tone captures the mood of the time to perfection. Directed by Brad Bird (who also helmed Ratatouille and another great cartoon on my list called The Incredibles) with a talented voice cast that includes Jennifer Aniston, Harry Connick Jr., Vin Diesel, Cloris Leachman, and others, this is one of the under-rated classics of cinema history. If you have never seen it, hunt it down and enjoy.
The Lion King - In 1994, Disney gave us an original animated story that would become one of the biggest hits of the studio's illustrious legacy, not just in terms of tickets sold, but also in terms of critical praise by both professional reviewers and the general public. The coming of age story of a lion cub who grows to become king of his pride is the end-product of a long list of writers if we judge it by the official credits. The film has a mythic scope and features the memorable music of Hans Zimmer and award-winning songs by Elton John and Tim Rice. Jonathan Taylor Thomas, Matthew Broderick, Jeremy Irons, James Earl Jones, Nathan Lane, Robert Guillaume, Rowan Atkinson, Whoopi Goldberg, Cheech Marin, and others all provide the voices for the unforgettable characters.
Akira - I could probably list a bunch of Japanese anime as my favorites, but this trendsetting classic tops them all. Made in 1988, it set the standard for not only future animated movies, but also some live-action motion pictures as well. Set in the future city of Neo-Tokyo, it has a number of iconic scenes full of action and sci-fi ideas that will burn in your mind forever,.
Snow White and the Seven Dwarfs - Disney's first feature-length cartoon debuted in 1937 and it still holds up as one of the best. It has humor and genuinely scary moments. Based on the Grimm fairytale, it is arguably Walt Disney's greatest movie of all time, and considering all the great Disney movies over the decades, that's saying a lot.
The Incredibles - Some might say that every single Pixar movie deserves to be on a "best" list. While I love many other Pixar films, including Monsters Inc., Wall*E, Up, Finding Nemo, A Bug's Life, (and all of them really), this story about a family of superheroes is fantastic from beginning to end. I dare anyone to find a noticable flaw in this movie (and if you do, I'll argue that you're nitpicking). Starring the voices of Craig T. Nelson, Holly Hunter, Samuel L. Jackson, and Jason Lee, it celebrates and spoofs virtually all the superhero stereotypes while embracing the greatness of the genre. I never grow tired of watching it.
Pinocchio - Another Disney classic, this 1940 cartoon has great characters, great action, great songs, and a terrific moral. It stands the test of time and still delights audiences of all ages.
Toy Story 2 - The other Pixar movie that made my list is the second Toy Story chapter. I think this is one of the best sequels ever made. Director John Lasseter and his production team know how to tell a story and it is obvious that the voice actors (Tom Hanks, Tim Allen, Joan Cusack, Kelsey Grammer, Don Rickles, Jim Varney, John Ratzenberger, Annie Potts, Wayne Knight, Laurie Metcalf, etc.) all had a great deal of fun making this film.
Who Framed Roger Rabbit - I was slightly annoyed to hear one of the critics on At the Movies list this Robert Zemeckis hit as one of the most over-rated cartoons of all time. This was a landmark film, seamlessly blending live-action and animation in a plot that combined some of the greatest cartoon characters in history all in one film.
Fantasia - This Walt Disney experiment is a true gem. Released during the same year as Pinocchio, it was not a commercial success, but it lives on as a creative highpoint in Mr. Disney's career as he endeavored to use animation to bring classical music to visual life. The anthology of cartoon segments included the sublime to the ridiculous, with "The Sorceror's Apprentice" being the highlight of the film.
Princess Mononoke - I've written about this movie before. Needless to say, I consider it to be Hayao Miyazaki's masterpiece. I'm a sucker for mythic storytelling, and it doesn't get better than this.
A Nightmare Before Christmas - Tim Burton's stop-action animated movie tells the tale of the king of Halloweentown, Jack Skellington, discovering Christmas Town. Full of masterful tidbits, it's a fan-favorite, and deservedly so.
Heavy Metal - Finally, I'll include a movie that many critics hate. It's a collection of short sci-fi/fantasy and horror cartoons, definitely not for kids, loosely connected by a plot device centering on a glowing green orb that seems to be the embodiment of evil in the universe (hey, it's just a macguffin as Hitchcock would say to move the stories along). The film contains a great music soundtrack and is full of violence and nudity, but it epitomizes the notion that cartoons should not be limited to childish fare -- the animated medium can also provide a creative outlet for other stories that might not work in a live-action format but might be perfectly suited for the limitless potential of the animated feature.
There you have it. Feel free now to bombard me with all the other cartoon movies that you love that I've left off my list. Or if you think any of the twelve movies I've mentioned don't deserve to be on a "best" list, then critique away! I'm all ears.