Timing is everything!
Of course everyone wants to "end up" with a (good girl) or (good guy) in the end. Everyone has their definition of what is "good" though. Just as a lot of women go through their "Bad Boy" phase where they won't give a "good guy" the time of day because he's "too nice" staying true to their famous quote: "We adore those who ignore us and ignore those who adore us" If only the "good guys" and the "good girls" were attracted to one another!
Many men also go through a phase where they just want to party and get laid by the hottest girls available. This phase often lasts throughout their 20s and sometimes into their early 30s. If they cross paths with a "good girl" they'll usually end up hurting her or they will spare her serious heartache by backing away because they know they aren't ready to cash in their (single life) cards yet. The typical 20 something year old guy just got out of a dorm or broke out of his parent's basement. The last thing on his mind is to settle down and become his parents!
Most women in their 20s who are looking to have a "serious relationship" with marriage potential would probably do better by dating men who are in their early to mid- thirties which have never been married. One man's opinion! :-)