I always end up being a girls 2nd choice.... I am not stereotypical mr.nice guy so I don't know why?

It sounds like you are the kinda of guy that would be a first choice! (which is surprising) but I spotted some problems which, us girls don't like. When you say that you flirt with a lot of girls and make your self available... It will make girls think your some what of a player... Even thought your probably not. You have to be careful about who you flirt with and make your self available with because girls like to tell girls things and when things go around that you flirt with more then one girl then they won't pick you... Girls want to know their special and the only one you have liked so much... And that you want them a lot... Believe those things are a must... But you seem like a pretty good guy so if you follow those guidelines believe me... A girl will pick you as their first choice:) and if you need any more help just email me