Some more "youthful" input
With women, I said Last. Because I've seen it so often, that just seems to be the case. alarikf is right though, IMHO... the school I go to (USC) tends to have a lot of the more well-off, "beautiful people", and I've gotten to know several after two years there. Unfailingly, all of them have had some sort of wildly unattractive neurotic behaviour or are extremely depressed. They can hold up the image of being a "normal", "sane" person for at most two minutes in anything going beyond superficial conversation. I know most people here also have a slightly sarcastic outlook on what exactly normal and sane are, but I think we all agree that self-destructive, malicious, sadistic, etc. behaviours are not "normal" or "sane".
However, my view on it at this point is I don't have time for that bulls#!t. I'm too busy worrying about handling my (overloaded) academic schedule, working, figuring out what I'm doing with my life, expanding my computer skillsets... while still sleeping enough, exercising enough, and eating right. Throw a relationship into that, and in 99% of cases I've seen, a few to several of those priorities vanish completely.
In the workplace, nobody likes the jerk, and the jerk will eventually get fired. On the way up "The Ladder", it pays to be the nice guy, since by showing a willingness to work with others, others will be more willing to help you out, and will feel better at looking to you for guidence (which is a big factor in determining who is management material).
Everything else... it really depends. It's not the same as in the workplace, because it's more difficult to remove the jerks. They have to commit a crime, be convicted, and put in jail for them to be "removed". We won't discuss the more vigilante way to "remove" them, but you can get some ideas from AT's "I just caught some punk" thread