Sometimes you just need a juicy, sloppy, American-style burger and this American-Serbian operation does a fine job, right off Knez Mihailova. Burgers come in three sizes: Single (325RSD), Standard (357RSD) and Big (445RSD) and you build-your-own-burger from there (Wisconsin cheddar, jalapeño, caramelised onions, Siracha mayo etc). The results are one of the better burgers you'll find in Europe.
The only fault here is the absence of standard yellow mustard (honey mustard will have to do!).