Dean/Jo
JO: Are you giving me the last night on earth speech?
DEAN: What?
JO: What?
DEAN: No....but if I was would it work?
JO: Sweetheart if this really is the last night on earth then I'm going to spend it with a little something I like to call self respect.
Jo Harvelle the only person in the world to turn down Dean Winchester.
I honestly thought that Dean really did honestly have feelings for her, he just didnt know how to act on them. And Jo understood Dean better than anyone else (except Sam obviously). They would've been really great together if the writers had just given them a chance.