I used to run great the day after drinking, but then something happened to me some time during my junior year of undergrad. That XC season I was able to split a 30-rack with a friend, get blackout drunk and sleep for 3-4 hours and then feel fine during classes the next day and run a great, effortless-feeling (or, at least easier-than-usual-feeling) workout in the afternoon (I actually remarked to my drinking buddy, who was also on the team, at the end of one of those workouts, "Wow, we should get blackout drunk and stay up until 4 o'clock every night!" My teammates and coach were, understandably, not amused [I was also kind of having commitment problems that year and admittedly did not race well]).
That spring, though, I went out and partook in a heavy, but not ridiculous, Friday night of drinking, and then had to lie down and take a nap in a park two miles into an out-and-back eight-miler the next morning (I'm sure I looked very, very homeless lying there in my short shorts with a week's worth of stubble and breath that reeked of keystone keg beer) because I felt so tired, hungover, and generally crappy; my teammates woke me up a little less than a half-hour later when they were on their way back in and I stumbled back home with 'em. I think I would have been made fun of a lot harder if they weren't worried about me puking on their shoes.