Ghibli will ALWAYS have a place in my heart! So many beloved childhood memories w/ them. I still, to this day, enjoy re-watching Spirited Away, Princess Mononoke, Howl's Moving Castle, Kiki's Delivery Service, Whisper in the Heart and Castle in the Sky.
The only movies i've watched are spirited away & princess mononoke, i have been planning on watching my neighbor totoro but i haven't had time to do that yet.
Toss up between Princess Mononoke and Spirited Away as prime Studio Ghibli with Whisper of the Heart close second/third. Grave of the Fireflies would have taken my personal top spot if it wasn't so damn difficult to re-watch.