which one

I always liked howl's moving castle best, but Kiki's Delivery Service, Arrietty, the dyptich 'Whisper of the Heart' and 'The Cat Returns' are fun. People also seem to really like Princess Mononoke, but I've never watched it

if by Studio Ghibli you mean Hayao Miyazaki films (which is what most people mean) Nausicaa of the Valley of the Wind is easily my favorite.

I'm tempted to get a laser projector