I get flack for my views on this all the time, but my own experiences have given me all the ammunition I need to defuse many of the counterarguments I get...
I firmly believe in sex before marriage, as I firmly belive in teaching kids how to drink BEFORE the learn how to drive. Does this mean I condone pre-maritial free-for-all orgies and hard liquor binge parties before drinking age? Hell, NO!!! I do, however, think that there is valid experience and knowledge gained beforehand on both of these, as well as emotional maturity. Again, though, it totally depends on the maturity of the person involved. There is that group of people that are of the "addictive" type and take things way too far and to a very unhealthly level.
In terms of sex, how in the hell do you even know what trips your trigger unless you've tried a few flavors along the way? You test-drive cars, right? You shop around for clothes, right? You pick your friends carefully, no? Sex in no way should be the defining characteristic of marriage(it fades as you age, or so I'm told), but IT is a very important one that further solidifies that bond between two people. Knowledge is power, so it is said, and walking into a PERMANENT lifetime committment such as marriage without "kicking the tires" beforehand scares the heck out of me.
It seems to me that our culture has it backwards on a few things, mainly due to biblical principle. I am a Christian, though a flawed one and like I said, my above views have gotten me blacklisted and riddiculed by a number of other Christians and moral stalwarts that I know. As I wasn't put here to specifically judge and condemn people on their actions (though, apparently some were, it appears), I won't go into the moral argument of pre-marital sex one way or the other, apart to say be your own judge on what is best for you, though heed warnings and advice on both sides of the table and choose carefully before plunging in.
I merely speak from my own experience and speak from other failed and successful marriages that I've seen. I will admit that some of the happiest marriages I've seen have been virgin marriages. I've also seen a number of them end in divorce and strife, due to neither party being "fufilled" by the other.