Beer is always a great and simple choice at a bar. They are also a good choice for men. For girls, you have a lot more choices, alcoholic slushies are becoming more popular. Malibu and pineapple juice is always delicious.
Some good bar drinks are Long Island Iced Tea, Cosmopolitan, Scotch and soda, Bombay Sapphire and Sprite, Baybreeze, and Rum and Coke. If you prefer frozen drinks, strawberry margaritas are good and so are pina coladas.
If you like beer, find out what's on tap! As for other drinks, some popular ones are: Caesar, rum and coke, gin and tonic (G&T), scotch, rye and coke, margarita, martini (many different kinds), mojito, etc.