Just about all of it, hahaha.
But, if I had to rank it:
1. My 1st girlfriend and I on our first night fucking on ecstasy. She was a little slut who was about 14. She looked like a pornstar and still does. I was 17 and she took my virginity earlier in our relationship. That shit was crazy.
2. When I cheated on that girl after 3 years with a tiny girl that I had been wanting to fuck since I was like 12. I was 20 now and she was 22. I grew up thinking that she was the hottest girl in my town but could never fuck her because the age difference was a big deal when you're young and I guess I just wasn't cool enough, haha. Now, I was and we fucked non-stop for about 4 days, about 10 hour at a time, literally. It was crazy as fuck.
3. First dick that I ever sucked. It was a HUGE, un-circumsized black cock and at a glory-hole. I loved it. I went home and kissed my girlfriend at the time without her ever knowing, haha.