If a girl isn't funny or witty, I don't date her. My girlfriend makes fun of me all the time. Likewise, I make fun of her. Then she tells me "I don't want to have a relationship where all we do is make fun of each other." I tell her "We don't. We also make love in my bed almost every night." Then she smiles and says something clever about my inability to perform when drunk, or something of the sort, and the whole cycle starts over again.
So to answer Norsemaiden's question, I love wit in women. I think it adds to the flavor of the relationship. Compatibility comes from a couple's ability to play off of one another. Part of a relationship is resistance. It's not all how the pieces fit perfectly together. Sometimes it's how the pieces don't fit together, but you find ways to get past such things. I appreciate wit in people, whether it's in males or females. If my girlfriend is clever or witty, then I know she's impressing and pleasing (in a coversational sense) other people. That makes me happy, because I know she can hold her own in a coversation.
I've heard this theory about men not appreciating humor in their significant others. Personally, I don't appreciate a lack of humor. Wit shows independence. I want to know that my girlfriend isn't reliant on me in a group situation.