Alright, for me, there's the dreaded toilet dunk (especially if it's a public bathroom). Condoms were tricky until I found out what works for me.
I still have to put them on myself. Letting my partners do so has nearly led to injury. Injury? Well once I was dating a really small girl and I started to bleed (I'm uncut and the tiny bit of skin, the frenulum I think, tore...long story short: I'm girthy, she was 5'1", we'd been drinking and I didn't use lube). Luckily, I was wearing a condom, so I didn't actually bleed inside of her, which would have been bad, but it bled *a lot* and we couldn't have sex while it healed.
I have yet to receive a decent bj without any painful tooth action. Don't get me wrong, I've received some no-tooth head, but it was only licking or sucking a little bit of it, which doesn't qualify as "decent" for me.
I also have only been able to put the whole thing inside one gf so far, which makes those "vibrating rings" that seem to be all the rage these days basically useless. Tried one, but I had to rest it midway down my shaft in order for it to have any hope of touching her. It didn't really do anything for either of us. Basically the same problem as the "pubic bone on clitoris" impossibility that 32745 described.
When I cum, sometimes I can't control how deep I'm going and I've hurt a few people, which isn't all that fun.
Finally, especially when I'm first becoming intimate with someone, we can't do it that often (once every 3-4 days) or she will get sore. This is fanfuckingtastic because when you're first becoming intimate is usually when you want to do it most often.
That said, the pros far outweigh the cons for me.