Haha! All of you are partially right about Stella. The Seinfeld episode is the one where Elaine throws her back out while visiting Jerry's parents and takes a powerful pain killer to attend a party. Jerry hurts his eye and has to attend with dark glasses. The rest is on the link below. I have an extremely frustrating GPS, partially because I live in a fairly mountainous region and her instructions (I call them destructions...) occasionally take me on wild goose chases. So, I use the famous Stella yell to yell at my GPS when I end up on the wrong road.
Seinfeld: Stella...Stella!!! - YouTube