Just Friends?

I have been thinking about writing this blog for a while now, and I figured it would be best to write it at a point that I could not think of anything else to write about. I could think of other things to write about, but this is the last blog of the semester and I appreciate all of the feedback that I have gotten from this class, so I figured it must be the perfect time. Because believe it or not, I want your opinions.
This subject has been long debated. Some say that guys and girls CAN be "just friends" whereas others say that they CANNOT. For the longest time, I believed whole-heartedly that they could. Why? Growing up I found that being friends with other females just made things difficult. One minute you could be planning a sleepover and the next you would be fighting because someone doesn'tlike someone else that you planned on inviting. If that's not the case then it would be something to do with how your best friend kissed your boyfriend. Basically, there was just too much drama. I found it much easier to hang out with guys. They always accepted me as "one of the guys" and I never had a problem with that title. I actually really enjoyed it.
My guy friends were always picky about who I dated and they would tell me their honest opinions as well. I always appreciated that and I would always do the same for them. I only ever dated one of the guys that was in our "group", but even to this day we laugh about that. I was pretty emotional when we broke up, but after a week I realized that we were not meant to have a long-lasting relationship. Heck, I don't even know if you can call what we had a relationship in the first place because we barely talked (even when we had class together) or saw eachother when we were "dating". I always joke that we had mute dates rather than blind dates.
I swear life was much easier (when it came to having friends) when I was single. The guys were always willing to hang out and joke around with me.When they thought that my relationship was going to last they would back off from hanging out with me. This always bugged me. I told them once that if I'm going to date someone then that guy was going to have to be okay with me having guy friends. Nevertheless, they still didn't come around as often as when I was single. When they had girlfriends they seemed to not want me around much either.
Some people say that this happens because guys really "only want one thing", but that is just really hard for me to believe. I know so many guys out there that are sensitive, down-to-earth, and truly nice guys. I just cannot see them only wanting sex. And no, they are not gay.
The thing that really got me to wondering if guys and girls could really be just friends was my engagement to my husband. I had been engaged before, but my guy friends knew that relationship was not going to get to the wedding part because I kept asking them what I should do since that guy was not right for me. When Eric and I got engaged however, my friends started backing off at first and as it got closer to the date they would try to get me to hang out with them if Eric wasn't with me. Sometimes I would and we would just hang out like nothing had changed, but when the wedding came, almost none of my close guy friends showed up. I was heart-broken at my own wedding. Some of them still text me, but they never want to get together with both Eric and I. It sucks to say the least.
So what do you guys think... Can we be "just friends" with the opposite sex?