As you probably know Miyazaki created many animes. This is one of his works, and like all of his works, it is simply amazing. Many people do not realize this but Most of Miyazaki's movies are intended for older/adult audiences, despite the fact that it seems like for children. Therefore even adults will appreciate his movies. The story is kind of slow in the beginning because it seems that the rising action part has to be long for the audiences to understand. It is after about 1/3 of the movie when it gets exciting. The story is just amazing and watching this will brings all the fantasies that you had when you were kid. The animation is beautiful, although if you saw all of his movies the character shapes and landscapes do start to change. I was little disappointed with animation because it wasn't as sharp and beautiful as his later works but it still surpasses most animations out there. Even if you are not a fan of anime this is a must see for everyone. I would give this movie 9.2/10.
BTW: Why is it spelled Rapyuta in Japanese version? Because Japanese language lack certain pronounciation that exist in English/latin, therefore it is easier for them to say "ra" than "la" and "pyu" than "pu".
Miazaki, only great ideas have come out of your head ever since you started some of the best anime films of all time especially this one. This was the first work of yours i have ever seen which may hold the answer to why I like it the best. The characters Pazu, Sheetah, dola were all developed I especially liked the view on colonel Muska in how he was your friend and your enemy at the same time.
The idea of a castle floating in the sky is just amazing, Miazaki I'm sure has one of the most creative minds in the world. I especially liked the background of laputa in which Pazu's father saw it which inspired young Pazu and sheetah to find it although Sheetah was already the Queen or Princess of Laputa. This was definitely my favorite Anime of all time.