Anywhere during OU weekend, that whole place is a party, just follow cars with lots of college chicks in it. Actually go downtown during the day and ask around, find out where some parties are at. The great parties move every year, different place but still a blast.
From the Texoma area, but I go party in Dallas. Lizard Lounge, Red Jacket, The Church, Bar Dallas . . . all those places. I strongly suggest the Lizard Lounge if your hunting for muff.