Thought I'd chime in here as well.
Red wine has come up as an obvious 'healthy' choice as far as alcohol goes. The only problem is that it's relatively carby, so if you're watching those I'd go for a drier white wine. If you're a beer person (like me) you will cringe at having to drink a Bud Select just because it's low on calories - its pretty devoid of flavor and life too. Beer is best kept to special occasions because any beer worth drinking has at least 100 kcal per 12 oz. (my opinion).
Aside from those two, if you are strictly watching calories then hard liquor neat or on ice is the way to go. If you're consuming alcohol and not eating much with it, most of what little you do eat will fuel your body's processing of the alcohol, so as long as you're in control that evening and don't impulsively go hot dog binging after a night of drunken revelry, you should be fine.
1) eat real food - more vegetables, moderate meat, moderate fruits, less grains, less sugar, less vegetable oils.
2) exercise - moderate intensity cardio, sprinting, heavy lifting, dedicated stretching and mobility.
3) live - relax, de-stress, meditate.
Disclaimer: I'm not professionally qualified to make any formal recommendations. I've just done my homework and I'm my own guinea pig. All of my data, unless otherwise cited, comes from a sample size of n=1 (me).