DC9 (upstairs or down, which is cool -- upstairs louder DJ music, but pretty cool alternative stuff, and downstairs is more mellow, straightforward bar; cool thing is you can do both depending on your vibe or if the energy changes during the evening)
St. Ex (if you want the DJ scene, but on a saturday it can be really crowded downstairs)
Pharmacy Bar (has a great feel & vibe, really good jukebox, great bartenders -- feels like a bar on the Lower East Side...).