I love to hear it too, since it means all's well with the flock. Mine often wakes up to crow once around 4:30am. We have a baby monitor in the coop, so you first hear a thump-thump-thump when he flaps his wings to warm up, then the crow. Now that he's two years old, he usually goes back to sleep after that, until it gets light. When he was younger, he'd keep doing it for up to twenty times in a row.
I recorded his crow with my phone, and use it as an alarm sound for chicken-related reminders. One of my long-term projects is to try to capture some of the other sounds they make - each one has their own distinctive voice.