I can't claim to have watched all of Miyazaki's films. I've got more on DVD than I've seen, and I'm savoring them rather than watching them all in a couple of sittings. I just finished watching My Neighbor Totoro for the first time, and (as is usually the case after I see a Miyazaki film), I've had to revise my list of the greatest feature-length animated works of all time.
Miyazaki's films are unique in that, although they may have different target audiences (Kiki's Delivery Service is geared toward a much younger crowd than Princess Mononoke, for instance), they all have a broad appeal. The animation is never anything short of stunning, the characters are well-rounded, and the stories are deep and captivating, yet self-contained.
My favorite still remains Spirited Away, the tale of a timid young girl forced into servitude in an spirit-world bath house by a mysterious sorceress after her parents are turned into pigs. (Never let it be said that any of these movies have completely grounded plots. I've yet to see one that doesn't rely heavily on magic realism, sci-fi, or a combination of the two.)
So far I've seen, and wholeheartedly recommend:
My Neighbor Totoro
Nausicaa of the Valley of the Wind
Castle in the Sky
Kiki's Delivery Service
In my collection, and waiting to be viewed:
Howl's Moving Castle
I've also got two other Studio Ghibli films on my "to see" list, Whisper of the Heart (which Miyazaki wrote and storyboarded, but didn't direct) and The Cat Returns. I passed on Pom Poko and My Neighbors the Yamadas, since they sort of snuck out of Disney's vaults without a lot of hoopla, but I'm planning to pick those up as well.
Please tell me I'm not the only person here who loves this genius's handiwork.