There are two things I really really enjoy about sex. Yeah, the orgasm is great, but I can have that by myself. In fact, many times the orgasm is better that way. But there's two things that definitely take a partner that I find most enjoyable.
One is the feeling on my skin when I first enter a woman without a condom. Not getting into when it's appropriate or not to have unprotected sex here. But you definitely can't get that sensation when using any kind of condom. And damn that part feels nice. You don't get that sense on subsequent thrusts.
The other is runnuing my hands over someone else's body, exploring every curve. The round softness of a bottock or breast, the hard bone of the jaw below the ear, the small of a woman's back or the back of the knee. I could probably spend hours running my hands over a woman's body that way.