I lost my virginity if you define it vaginally at 17, oral at 16. It was with a boyfriend who I cared about very much, and he was extremely respectful and waited until I was ready to try things. He had had one other sexual partner, who was a long term girlfriend before me. She was a brilliant, confident, person, and I don't think their relationship was inappropriate. He was either 18 or 19, but only a year ahead of me in school (he had a fall birthday, I had a spring birthday), so although he was older, he wasn't much older.
The first couple times we tried, I bled and it hurt. However, he stopped whenever I asked, and was very gentle about it. After about the third time, it became very enjoyable for me. I didn't learn to orgasm until my 20s, but it still felt good and I enjoyed the physical intimacy. We started experimenting with different positions (69ing, etc.), and with a little bit of light kinky sex at that age. It was a great adventure. No regrets. We are still friends on facebook and would probably catch up and get coffee if we were both in our hometown at the same time, although as we have gotten older, we have less and less in common. I generally feel like having sex in my teens was a positive experience, and college would have been much more overwhelming for me without having had sex with someone I trusted beforehand.
In college, I went through a wild, drunken hookup phase, and I guess I was lucky that I did not get in any situations where I felt violated or where we failed to use protection. There were a few embarrassing situations, and a handful of heartbreaks, but all this talk about how that phase of life is damaging to people is just not at all my experience. Now I am happily married, and I feel like I had a range of experiences before meeting DH. DH and I met at 22, and were married at 24 and people ask me if I regret not experiencing more before committing myself, but I feel like college more than fulfilled that curiosity for me.