No doubt that Pixar makes some great flicks. That being said, there's a reason that Hayao Miyazaki, as a director, is at the top of my list of animation directers that I recommend. His body of work is impressive.
Nausicaa of the Valley Of The Wind (also known as Warriors Of The Wind)
Porco Rosso (this movie still has me in stitches at times)
Princess Mononoke (saw in theaters during U.S. theatrical release)
Spriited Away (saw in theaters during U.S. theatrical release)
Howl's Moving Castle
Laputa, aka Castle In The Sky (saw this in U.S. Release the first time around, before Disney took interest in Miyazaki's collection)
Kiki's Delivery Service
My Neighbor Totoro
Miyazaki was also involved in the project concept for The Cat Returns (Anne Hathaway, Cary Elwes, Peter Boyle and Elliott Gould were among the voice talent on the English/U.S. release for this one)
His current movie, The Wind Rises, is currently in limited U.S. Release. Hollywood voice talent on this one includes Joseph Gordon-Leavitt, John Krasinski, Emily Blunt, Martin Short, Stanley Tucci, William H. Macy, Elijah Wood, and other notables.
The Hollywood talent which has lent their voices to Miyazaki's work for their U.S./English Releases is also impressive, with said actors/actresses jumping at the chance to be involved. Here's a partial list.
Patrick Stewart, Gillian Anderson, Cate Blanchett, Matt Damon, Tina Fey, Choris Leachman, Liam Neeson, Lily Tomlin, Betty White, Anna Paquin, James Vand Der Beek, Uma Thurman, Edward James Olmos, Michael Keaton, Brad Garrett, Christian Bale, Lauren Bacall, Billy Crystal, Susan Pleshette, Billy Crudup, Claire Danes, Minnie Driver, Jada Pinket-Smith, Billy Bob Thornton.
It should be noted that the above films were released in the U.S. as part of the Walt Disney catalogue, at least for the U.S. versions.
Nausicaa was my first introduction to Miyazaki's work, and I've been a fan ever since!
In other news, I very much enjoyed:
Starship Troopers: Invasion
Final Fantasy: The Spirits Within (yes it's a bit slow, but it's a beautiful movie)
The original Wallace & Grommit trilogy (Aardman Animation):
A Grand Day Out, mostly for the mice with the glasses,
The Wrong Trousers (Academy Award Winner BTW),
and A Close Shave (also won an Academy Award)
Also, Wallace & Grommit: The Curse of the Were Rabbit (also won an Academy Award)
Aardman Animation was also involved with Chicken Run & Flushed Away.
The CG Appleseed releases were awesome! (Appleseed and Appleseed: Ex Machina)
The Ghost In The Shell movies were also enjoyable.
The Warhammer 40K Ultramarines Movie probably won't make anyone's top 25, but I very much enjoyed it. Nice voice talent too!
Wizards, Fire and Ice, and Heavy Metal were hella awesome in their day, and still rather enjoyable today.
Akira should probably be mentioned.
I'm going to throw in a couple of Robotech movies here. Macross Plus is a nice ride, and the Shadow Chronicles REALLY needs sequels, they were off in a nice direction there.
The Ice Age movies are fun. Also the Shrek movies.
Megamind was fun. Really it's nice to see animation now taken much more seriously here in the U.S.! For a long while there our standard seemed to be Bambi and Cinderella...
Oh, and to close things out... Bambi vs. Godzilla!