I very much enjoy pegging my partner. Such a switch in the dynamics of bedroom play really give us a refreshing rush, and I know it's really his long-time fantasy he never confident enough to play out, until he was with someone as comfortable with sexuality, not to mention toys, as me, so, it's really intimate, knowing he decided to share that with me, and trusts me enough to let me do this for him, so there is also that aspect of it. It really makes me feel like I'm someone special to him.
He's not the only one who gets enjoyment out of it, however, we usually both leave the sheets pretty soaked, I love a good power rush, and pegging delivers that in spades. It's a feeling I don't think I could get out of anything else.