ZAGAT for Android This is the Grand-daddy of all restaurant review apps-and for good reason. The thing that makes this app worth buying is the ease factor-it eliminates the need to carry around a physical guide, but has all the same info.

Yelp Besides the fact that there's hundreds of awesome reviews and useful information, the aspect of this app that I really love is "monocle". You can stand in a room and spin around and the app will use your camera to display which restaurants are open, how far away they are, and how many stars they get. It's fun, and helps you plan!

Urbanspoon I love this app when I have no idea what to eat because I use the random spin feature in the slot machine style interface to randomly pick a restaurant for me.

MenuPages The reason I keep coming back to this app is its scope. It has every bit of information you'd ever need about a restaurant, including their full menus, which I love.