Bad Hygiene

Low Vocabulary and redundant use of words

Bias

Lack of structure or ambition (in general)

Lack of understanding

Lack of awareness and concern (especially of other people)

Lack of common courtesy and respect

Lack of appreciation

Lack of intelligence

Lack of experience (in certain areas which usually means they are one of the above if not more)

Lack of confidence (in general), will power, and courage

Lack of excitement

Self-importance

Lack of straight, thought out, standards of morals and ethics.

Lack of spine (confidence/courage/morals)

LIARS

That's about it. If you dig deeper into each one of those you get more of what annoys me. Just so you know, even with all of that I have managed to find someone and she is gorgeous, which doesn't hurt. ;P

This isn't only for turn-offs though, I won't conceder you a true friend if you're most of the above. Confucius has said "Never contract friendship with a man that is not better than thyself". That's pretty much what I go by. So my last and most important one is obviously:

IF YOU'RE NOT A FRIEND