It's FAIRLY stereotypical, but the births of my boys were mine. For the eldest, it was that moment, in transition, when I literally said "this is really fucking cool," just before his delivery. For the littlest, it was the entire (incredibly fucking fast) labour and delivery (except the back labour. NOT a good feeling). I caught him, and cut his chord. It was incredible. I need to note here that it's not JUST because that's when I met my boys, which is, of course, glorious. But, almost more importantly (for me), it's when I recognized the primal, vicious strength I possess. I learned to completely let go in those moments (I am a BIT of a control freak), and it was fucking stunning.
(Please note: I am NOT one of those orgasmic birth folks. It hurt. A lot. )