I would add Anya from Buffy TVS. Technically she is a 1000 year old ex-demon, but even when there are flashbacks of her human life, she is very eccentric. Everyone complains that she is too literal. She doesn't understand social niceties, humour, or sarcasm very well. Most of the characters become uncomfortable when she tries to converse with them. She is very fixated on several interests and isn't interested in other people's problems unless they affect her.
For example:
Anya: I don't talk to people much. I mean, I talk to them, but they don't talk to me, except to say that, "your questions are irksome," and, "perhaps you should take your furs and your literal interpretations to the other side of the river."
Anya: [to a customer who just finished her purchase] Please go.
Xander: Anya, the Shopkeepers Union of America called. They want me to tell you that, "Please go" just got replaced with, "Have a nice day."
Anya: But I have their money. Who cares what kind of day they have?
Xander: No one. It's just a long cultural tradition of raging insincerity. Embrace it.
Anya: [to customer] Hey, you! Have a nice day.
_________________
?To be yourself in a world that is
constantly trying to make you
something else is the greatest
accomplishment.?
-- Ralph Waldo Emerson