London's Chinatown, wedged between Shaftesbury Avenue and Leicester Square, is the go-to destination for locals wanting to grab some great food before a show, or after a big night out. There are endless good restaurants along these backstreets, some of them seriously fine, and some for budget diners (take a bow, Wong Kei). There are fabulous Chinese grocers, where you can get all the ingredients you need for DIY Asian cooking. And there are a few brilliant bars (including the hidden Experimental Cocktail Club).
Try to get a recommendation from a local before you go, so that you don't end up being overwhelmed by the choices. Mine is dim sum at Leong's Legend.