sheisaprincess,
While Greek Life isn't for everyone and that doesn't make anyone "better" than anyone else, know that Sorority Recruitment, like job intervewing, is a very subjective process. You gave formal recruitment and a colonization a try-- you met new people and learned a lot about the interviewing process. Good for you!
Doubtless, in your time at your university, you've learned a lot of new things, made tons of friends and shared some unforgetable experiences-- that is what college is all about! Don't feel bad about not joining a sorority-- you are on the cusp of something wonderful-- GRADUATION! You get to join the ranks of the soon-to-be-employed. As you head into the homestretch of your undergraduate experience, focus on school, professional networking and interning. You have bigger fish to fry as a graduating senior this May.
Having a college degree is important, but having professional connections and internship experience are doubly important! Your recruitment experiences have prepared you for what to expect in a group interview and a private interview-- launching you far ahead of many of your peers! You know how to dress, the questions to ask and how to behave. These are invaluble!
A great group to join upon graduation is the Junior League. This is a volunteer organization of women from all walks of life; most of whom are well educated career woman. The league does great charitable works, high-end fundraisers and social galas where you will meet tons of like-minded women (and cute men, too!). Check out the Association of Junior Leagues International to learn more about the chapter near you:
http://www.ajli.org. Great opportunities await!