Tuff choice but I have to go with a Saphire gimlet, up, shaken to hell.
Saphire tonic or Mandarin tonic if it's going to be a long night.
Anything "up" I want shaken to death, so there are big flat crystals of ice floating on top ya know?
When it's cool out or I want something richer I go with:
shot of espresso/ four count of your favorite vodka/ one count frangelico/ three count kaluha.
I think I'm gonna get tore up this evening, thanks for the inspiration all.