My go-to liquor drinks are either a dry martini, gin & tonic (diet tonic if they have it) with a big twist of lime, or a jack & diet coke. All are around 100 calories or so. I don't drink as many bc I sip them slowly! As far as beer... Guiness (on draught) or Sam Adams Light are great for lower calorie beers, but then again, if I'm going to spend the calories I'll usually stick to 2 or 3 Magic Hats or Fat Tires and just plan them into my week! I like good, tasty beer!
Drink LOTS of water. Eat food (as in, don't skip a meal to drink more calories). And whatever you do DO NOT weigh yourself the next day. I know whenever I go out, I retain water like crazy for a couple of days, then it all shakes back out to normal.
Or just drink water with some lemon/lime and have a great time anyway! Being the DD is always a good excuse. Save lives and your waistline!