My biggest pet peeve are the women who date someone for who they want them to be rather than who they already are. Too often have I heard "I really like him, I just need to get him some new clothes." Or, "He'll be perfect once I change his opinion on politics." If you like a person, then like them for who they are. Appreciate their quirks and accept the whole being. If you really need to change something to make them acceptable to you, then why are you dating them in the first place?
I used to work with a perfect example of this phenomenon. 'A' was not a perfect person. However, being both beautiful and vapid she had the perfect facade of ditz and slut to make men fall at her feet. And fall they did. With each new man came a laundry lists of things that needed to be changed, from their hair to the way they walked. One such man made it to living with her before she began to change him. Another never made it to the first date. When I left the company we worked for, A had yet to be happy with a single person who crossed her path.
Everyday I look at my boyfriend and think about A. When I started dating J she started tutoring me on how to get him to change his look. In her opinion, his punk look and multiple piercings weren't socially acceptable. (In her defense, she had never seen me outside of the Land's End work clothes our company provided.) Always insecure, I started to listen to her, and started to nitpick all the small things that weren't "perfect" with my man. Eventually I stopped and looked at him as a whole picture. The happiness that followed makes me feel sorry for A and the women like her in the world. I know that they'll never find their perfect man - they're too busy trying to create him.