The fights I watch will depend on where I am in training.
If i'm 3-4 weeks away from a fight il watch the fights the morning after rather than stay up til 3 or 4.

Also, if i'm training I'll watch fighters that "apply to me." Guys who's style's I try to emulate and watch their moves to learn something. (I often find myself obsessively watching Hagler, Monzon, JCC and lately Whittaker.)

Otherwise I watch or rewatch a fight a day. Usually by guys like Leonard, Benitez, Arguello, Pryor, Ali, Hatton, Mayweather and Hearns.