Fairly new to anime TV Shows. Which series have the best/most addicting storylines/arcs?

I'm in love with Studio Ghibli (as I'm sure many of us are. Spirited Away is my favorite animated film) but not overly familiar with the TV Shows. I love anime/cartoons with continuity and excellent storylines, and am wondering if you guys can give me some suggestions. I'm talking about shows so good and characters you fall in love with so much that's it's almost depressing when the series is over! I love good story arcs and mysteries! Thanks guys!