I saw some discussion about Ghibli-esque RPGs on the NSR discord, and it made me think about what systems I would use for games inspired by the Studio Ghibli movies. Of course, the Ghibli movies are quite different from each other, so I picked out a system for each one.
And it's only the Hayao Miyazaki movies, because those are the ones I've seen.

Nausicaä of the Valley of the Wind
There's dynamic action and big weird monsters. A girl gets shot with a machine gun and keeps going. Dungeons & Dragons 4th edition should work great!
Castle in the Sky
I think there's like three dungeon crawls in this movie? Any old-school D&D would be fine, but I'll go with Tunnels & Trolls. Pazu would rack up a lot of AP from all the stunts he has to do.
My Neighbor Totoro
So the kids are doing a bunch of esoteric stuff with the spirits and the adults don't notice anything is off, but the magic is real because the mom got that corn in the end and it did cure her illness. Sounds like Mage to me! Adults = sleepers.
Kiki's Delivery Service
Cargo delivery, patrons, random encounters, desperately trying to stay afloat in a harsh gig economy - Traveller is a perfect fit for this movie, if you replace the spaceships with broomsticks. I do want to add some Call of Cthulhu mechanics though: if you run out of SAN, you can't fly anymore.
Porco Rosso
Your life is a failure, you're out of money, the secret police is looking for you, and you're a pig for some weird reason. Yeah, you're in an Electric Bastionland game.
Princess Mononoke
There's a lot of fighting in this movie, with lots of body parts getting slashed/shot/bitten off. Also a demon infection disease. I think Rolemaster is the right system for this one.
Spirited Away
This movie is all about working a shitty job while dealing with dangerous otherworldly entities. It's Warhammer Fantasy Roleplay! Just need to write up a Bathhouse Worker career.
Howl's Moving Castle
A small team of weirdos try to save the world from devastating war. F.I.S.T., right?
Ponyo
So the whole world gets imbalanced when Ponyo leaves the sea, and that causes a series of apocalyptic events. MÖRK BORG has a good mechanic for that!
The Wind Rises
Yeah, this is just a dude who makes planes and stuff, and then his wife gets sick. For games set in contemporary times with little to no combat or supernatural stuff, I like to use GURPS. Bonus: If the Jiro player actually wants to design those planes, I'm sure GURPS has extremely detailed rules for that.
The Boy and the Heron
Now this movie is far out. The boy moves between a number of strange locales with strange people, and it's probably an allegory for something or other. I will choose Between the Skies for this one. It's very good at strange.
And that's all of them!
Until Miyazaki makes his next final movie