Cafe Madrid in Uptown has the best tapas.
Jack's Burger House in Snider Plaza has the best hamburgers. The other locations are utter mistakes; only eat at the one in Snider Plaza on Hillcrest. I am in the third generation of my family to eat at Jack's, and so are most of the people who go there. Sit at the lunch counter if you can get a spot.
Bubba's in Snider Plaza has the best fried chicken I've ever eaten - the best thing is to get your food to go and take it back home so you can eat it while watching hockey.
Brother's Pizza at Fitzhugh and Travis has the best New York-style pizza.
Sevy's in Preston Center has the best venison.
The Samba Room tuna appetizer, cooked rare, is the best tuna in town. Try the plaintain chips, too. The best entree on the menu is called Loma - beef tenderloin cooked on a stick of sugarcane with muchrooms and watercress.
Tramantona has the best osso buco. It's a great small place and is perfect for a date.
Sol's Taco Bar and Tango Lounge in Deep Ellum has really good arroz con pollo and also has a kosher menu - the bagels are flown in from NYC. I hear it has something to do with the water
Cafe Istanbul on Lover's Lane near the Inwood theater has good food and a belly dancer on Friday and Saturday nights. I had the unfortunate experience one evening of watching my father do shots off her stomach. Have you ever laughed and cried at the same time? I'm scarred for life.
Everyone argues about the best barbeque. If you're visiting from out of town, though, go to the little shack on Inwood at Harry Hines and get a chopped beef sandwich and onion rings. It's the first location of Sonny Brian's barbeque, and it's won tons of awards and is an excellent example of Texas barbeque. They open at 11 and close when they run out of food, which is usually around 1, but they often run out of ribs at 11.30 or so.