There is a place called "Ocio"; it's a chill-out bar and they offer great Pisco sour.
Ultima Frontera is an alternative/student bar, always packed, great decoration in a building under very big trees and wide food menu. Located at Pérez Rosales esquina Yerbas Buenas 787.
CervecerÃa Kunstmann (http://www.cerveza-kunstm...) for those who love beer; this tastes so good!. You can visit the restaurant in the factory, just 10 minutes to the downtown.
You find a dozen of places for dance or drink in "Calle Esmeralda", a short street in the downtown.
For Gay People there is a Gay Disco named Tequila at isla teja Fridays.