There are a number of great Studio Ghibli titles that I recommend! Princess Mononoke, Porco Rosso, Spirited Away, and My Neighbor Totoro are some of the more fantasy-style films, while From Up on Poppy Hill and Only Yesterday are lovely examples of the more realistic ones. (Grave of the Fireflies, the one set during World War II, is pretty heart-breaking but beautifully animated.) I'm glad you liked Marnie -- I've heard good things about it, though I haven't yet had a chance to see it myself.