Melanie Lynskey stars as Rose on Two and a Half Men.  Rose is Charlie's neighbor and after a one time fling becomes his full fledged stalker.

Rose, despite her craziness, is actually quite intelligent and went to both Princeton and Stanford.  Rose moved away to London but still makes the occasional appearance.

Rose Quotes

Charlie: Let me tell you something about feelings. Feelings are like your mother's breasts. You know where they are, but they're best left unfelt.
Rose: It's an interesting analogy, but may I point out that a mother's breasts are a source for nourishment and comfort?
Charlie: Yeah, well, my mother's breasts were a source of silicone and Russian vodka

...We're both like two lonely socks that want desperately to keep someone's feet warm, but we don't match up with any other socks. So all we can hope for is to be a dust mitten or a hand puppet

Rose

Two and a Half Men Quotes

Charlie: Oh, try MalibuPuddingGirls.com.
Alan: Pudding Girls?
Charlie: Trust me.
Alan: Oh ... ew.

Chelsea: I just think it's ridiculous that we're engaged and we're not living together
Charlie: Well excuse me for being old fashioned. I'm just not comfortable with us living in sin
Chelsea: So you think we should stop having sex?
Charlie: No no, it's not the sin I object to, it's the living in it