PONYO!!!
I also love Space Jam as well. Space Jam is one of the few movies that can make me feel little. Mostly, because it is an important and treasured part of my childhood. I also really like The Rugrats Movie, Rugrats in Paris (after all, that's how my nickname 'Kimi' was born. :3) and the Land Before Time movis are also very special to me. I also like the American Tail ones because those also make me feel little sometimes.
I also really like the original animation Disney movies. They have more of a nostalgic little feel for me at times. My favorite Disney movies from the 90s include The Little Mermaid, The Lion King and others I can't think of atm. Oh, and it's more recent.. but I also LOVE Zootopia!