Worst hangover I can remember was after a night of downing Rusty Nails. That drambuie is a vile liquid.
Faves:
Cuervo gold margarita, on the rocks, no salt, floater of grand marnier
My dad's gin and tonics (5/1, Tanqueray gin/tonic)
Pyrat rum, neat
Stoly, so cold it runs like syrup, neat