Bordeaux is lively during the day and continues throughout the night. If you're looking for a bar to hang out with friends or to enjoy watching a football match, head for La Victoire, as most of the pubs and bars of the town are here. Virtually, all the shops in the surroundings of this area are bars, and you'll likely be able to find one that suits your needs.
If you prefer dancing or clubbing, most of the night-clubs are on the Quais, near the train station. From rock to disco, dance to techno, you also have a lot of choice.
While the entrance is free to the majority of the clubs, don't get there drunk or you will not be let in.