How to not be a "nice guy" or a jerk

Just be yourself.

And what's wrong with being "nice guy"?

I have too much testosterone and competitiveness, I can cut it down, but I cant be a nice guy and not feel uncomfortable.

Just be you and that way you will truly find the right one who appreciates and loves you for who you are. Being something else will only lead to frustration down the line.

Try to be creative and different. look at the boring people around you and make sure you don't look like them. Also, keep good conversation, be witty and more importantly show yourself independent. Of course, all this must reflect you in your very personal way

about the nice guy, you are afraid of that "he's-a-great-friend-but-I'd-never-date-hi m" image aren't you ?

Yes, I'm terribly afraid of that image.

I was that guy too, but that one girl will come around and realize how lucky she is and before you know it shes stuck with you :p

You are asian, you can't help it man. It's in your blood to be excessively nice and not be noticed by womenfolk.

Partly joking there =P, partly, though it is a trend due to our culture.

Nothing you can do about trying not to be nice man, trust me, I've tried. If you have even a sense of honor, you can't get out of that "great sweet guy friend that she'll not consider dating material" cycle. Why, because the nice guy's conscience won't let him do otherwise. It's a lonely path, I think you and I spoke about this before, but maybe one day man, you could end up like wuturuva.

There is one exception of course, get a girlfriend that you get attached to, who treats you like doo doo, cheats on you, breaks your heart and assassinates your favorite puppy or something dramatic. Then you could end up like some of those unfortunate guys who became jerks because of their past experiences with their ex.

So what I'm saying is, don't think too much about trying to change who you are, it just creates unnecessary stress. What the people above has said is generally true. Though you should try to do something about that super competitive jerk, I don't know what you mean by that, but it doesn't sound healthy. If by that you mean, you are highly competitive and make a big deal about winning, the best cure I could suggest to you is lose and learn to accept the loss, even try to laugh it off. But like I said, I don't know what you are talking about.

P.S.

Just venting a bit here =P
But TONS of things is wrong with being a nice guy.

My advive to you is to be strain forward honest and nice. In doing this your not lying to them, they get the picture right away but your still nice about it.