Ever watched Pulp fiction? If you know the scene where John Travolta talks about 5 dollar milkshake and you want to try something similar go to the Intergalactic diner.
Perfectly located in two locations on Vracar and Zemun you can try some of the best burgers in Belgrade. Feel the atmosphere of a full American diner. Oh, and the jukeboxes work too, just bring some 5 RSD coins or ask a bartender for coins and play some evergreen and rock music.
Need some tips? Try Multiverse or Enterprise with Chili cheese fries on the side.