Deborah, when she has her I'm-so-very-pleased-with-things smile. She's so wonderfully animated that nothing seems to capture her personality as well as cartoons.
This is one of my favorite quick sketches of Deborah, from the early 1990s. I digitized it poorly, and only found the original very recently. However, my awesome friend Rich did some digital magic and surprised me with this great simulated brush-and-ink reconstruction: