Fair is fair. Here are my answers:
1. Awkward Sex. I am an awkward person generally, so sure, but I don't think I've ever felt like the entire episode was awkward. My first gf/high school sweetheart/wife and I were both virgins, and we each thought the other was a perfect being, so although our progress together was halting and tentative, it never felt particularly awkward. In a sense, we didn't know enough to be awkward. More generally, I've had plenty of isolated incidents of head banging, teeth banging, penis slips out near the end and wham! bent penis, condom breaking, you thought she knew it was condom off but she thought it was condom on creampie, crying out x's name during sex with y (only once, thank God), gf buried in collapsed couch, fold out bed, cot, or bed.
2. First Time You Knew What You Were Doing. My first and I were humming along with great results all around after the first few times. We probably knew practically nothing, but we were both having a fantastic time, and this question is certainly a subjective one.
3. Zero-Inhibitions Sex. There was this one girl. Third date, she shows up on my doorstep wearing an overcoat with only lingerie underneath. I carry her straight to the bedroom. First time we've had sex. As we're wrestling there, she says, "slap my tits." I had never intentionally done anything that might be painful to a woman, so I gave them something more than a tap. I'm a hugely built martial arts guy who easily outweighed her by a factor of two. She says, "much harder." She taught me things. She got what she asked for, and we had a very memorable night that improved my lovemaking from that night on.
4. Make-Up Sex That is Worth the Fight. So many times, but not memorably. When a relationship is growing, the sex is always better than the fight. When a relationship is collapsing, it's never worth the fight. The times I remember are the latter, and you don't want to hear about those. I suppose the former are forgotten along with the disagreement. I haven't argued much with any of my SO's.
5. Sex So Good You Accidentally Break Things. I am enormous, as I said, so I break things even if the sex was bad. Memorable times have been when I demolished an IKEA bed frame while continuing to fuck her silly -- that time was good. One girl owned this huge wrought iron king size bed that weighed maybe 600 pounds. Woke up one morning and realized I had fucked her so long and so hard the night before that I moved the bed diagonally across the floor about a foot. She liked it hard very, very much and so had offered me lots of encouragement throughout the night. Nice oak floor. Four deep bad scratches. That time was also very good.
6. Morning Sex That Makes You Late for Work. I've never had a job where I was required to clock in and clock out at exact times. I know, I am terribly spoiled, but not unhappy about this. I have called in sick so I could keep having sex all day.
7. OMG-I-Can't-Believe-I-Did-That Sex. Absolutely. I remember a time where wife #2 and I went camping with five other couples. These were ordinary, professional, fairly straight-laced people all but one of which we'd known for years. Some we'd even been hiking or camping with before. My wife and I were very hot for each other that night; there's something about a new venue. There was a lot of very discreet rustling but little else coming from the other tents by the time we were getting very serious. We both felt really intense, and soon she was turning 50 shades of pink trying to keep her sound in, then she suddenly gave up and let out this deafening howl. She had been really bottling up the sound for a while, and she was normally very vocal. It was one of those incredible sounds, and I thought, at least, everyone would know it had been her, and maybe they did. Some giggles and chuckles from other tents followed in the deafening silence. That opened up the floodgates. Lots of whimpering and even louder sounds from at least two of the other women after that. She stopped holding her breath and made her normal amount of noise, which was not deafening, but must have been pretty exciting for the others to listen to. She has a beautiful voice. I like to make a lot of noise too, so fuck it, I didn't hold back at the end, but didn't make a ton of noise like she had. I guess I was shy. Occaisional growls and grunts from other guys. I remember waking up later, and somebody was having noticably unquiet sex. This happened two or three times during the night. We took our turn before dawn and then fell asleep until most of the others were rummaging around outside already. In the morning, it was not openly discussed.
8. The Never-Again Position. Less sexual positions and more surfaces. The beach is very dangerous but not quite in this category. Just say no to doing on the playa. Plenty of surfaces that were too hard and scuffed her knees, back or other parts. Couches that were too soft where she submerged under me and I had to get off. Bouncy beds and matresses where you could not get into any kind of reasonable resonance that worked.
9. Super-Loud Piss-Off-Your-Neighbors Sex. Stand out memorable times when wife #2 (the camping one) and I were first dating. Extremely loud sex in the bedroom of my condo in Larkspur. Nastygram from downstairs neighbor taped to my door talking about how her daughter had been permanently scarred, etc. We shut all the windows in the place, which probably helped a little.
10. Goodbye Sex. Most memorably, I tried to break up with wife #3, the current Mrs. Sweetums, at least three times. I thought I was bad for her, and I was probably right. I couldn't/wouldn't break up long distance, and this led to me breaking up with her and her crying and screaming at me a couple of times after the best sex I'd had in my life. I felt pretty guilty, but I couldn't help myself. I had to have that one last taste. But she knew me too well. She would invite me for coffee the next week to "talk about it". She would wear a low cut dress with a shiny necklace and recapture me. Now that I'm legally captured, she never wears dresses. :-(
11. Sex With the BEST Possible Soundtrack. I'm very distractable, so I don't really play music during sex. I expect my partner has on occaision, but I'm pretty single-minded and don't remember a single song I've ever had sex during.
12. The One Where Your Partner Does All the Work. This is on my bucket list. Being proprtionately huge, cowgirl and reverse cowgirl don't work on me; I'm just too wide-hipped. Even a girlfriend I had once that was 6'1" couldn't do it comfortably. And the squatting thing, I guess I've never had a girl athletic enough to do the whole thing that way. I've had her share the work by pushing backwards in doggie style, but I'm just too tempted to participate with that one.
13. So-In-Love-It's-Stupid Sex. So many times. The most memorable of these for me was a time after wife #2 had cut me loose. This woman and I had taken a year long professional course together, and after that she moved away, but we were entrepreneurship buddies, and we had these weekly phone calls that turned into daily calls. She lived in Washington state and I lived in California at the time. We were always SFW flirty with each other, but on these calls, we started being NSFW flirty all of a sudden, and I found out she had broken up with her SO. Then we got flirtier and flirtier and FLIRTIER until we were practically having phone sex. Then I said, "hey, why don't I come up for a visit? We could hang out and see where it goes." So I flew up there, and we were REALLY anticipating being together, because we'd been hot for each other for 18 months, but you know, things had been in the way. That first weekend with her was off the charts. We were very volatile together, though. I got tired of her running away in fear and then wanting to come back just when I had gven up on her and something else was getting promising.