As for regards to number one. I would have to say GSP / Serra was the most shocking upset. Aldo / Conor is also a good answer. Never thought Aldo could lose that quickly.
Anderson had been clowning and keeping his hands down in fights for years. It was only a matter of time until he got caught.
Holm vs Ronda wasn't shocking at all. Ronda whilst very dominant in her prior fights, clearly had elementary striking, especially on the defensive end. And she came to think highly of her striking, stating she could knock men out, and so forth, giving her a false sense of security on the feet. I forget which fight, but I remember her throwing wingers with absolutely zero concern for defence. Thats exactly how one would picture her losing, ie. not by a grappling exchange for example.