Who makes the best hamburgers?

Hamburger Mary's Los Angeles

You're asking in the fast food section, so you probably mean which chain. Many small chains are members of the better burger movement. They all generally beat the major chains.

Assorted details -

In-N-Out - Their standards are different west coast versus everywhere else, so off the west coast they don't stand out. They under cook their fries for some reason so they need to be ordered "well done".

Five Guys - Their fries stand out but there are differences location to location. Some locations double cook their fries and they are beyond wonderful.

The Serbs. Pljeskavica are Serbian hamburgers popular in one form or another throughout the Balkans.

1 pound ground beef chuck
1/2 pound ground pork
1/2 pound ground lamb
2 cloves garlic, finely chopped
1/2 cup finely chopped onions
1 1/2 teaspoons salt
1 tablespoon sweet or hot paprika

Personally, I think Burger King makes the best hamburgers.

Popeyes

Popeyes

The Habit Burger and Slater's 50-50

Griff's Hamburger in San Antonio.

The best hamburger is not who ,but is how to make it .To cook the stake or hamburger ,temperature is most important element .
Just mixed onion ,salt and pepper to the grind meat,let it rest in room temperature for at least 2 hours ,then make the bergeres .To grill you need to rest the hamburger after both side are bit cook ,this will help joice of the meat stay in the meat and not turn to the dry meat .After both side get enough cook to hold the meat together ,you need to take them off the grill and rest them in a dish till they get cool and again return them to the grill and cook in medium heat ,never squish the meat on the grill.
To cook in the pan do the same as long as both side get golden color ,put them in rest in one dish for 5 minute and again put the back and cook till meat be juicy and soft .
The best combination of fat and meat for hamburger is 20% fat and if you want to have more tasty meat grind some bacon and mix with the meat .When fat is start melt in the meat it create a layer that is keep the juice inside the meat ball .
Out door hamburgers are not fully meat and they made in factories by combination of the fat ,flour and unwanted parts of the meat that is not useful for the meat markets .Ingredients mixed with those hamburgers are cause to taste like meat and what your really eating in fast food hamburgers is not actually meat .cause meat after mix with ingredient can not stay good for long even in freezing temperature and will contain bacteria .

Close to home. 2 brothers makes a good burger. Many small places do each is spiced a little different. Only way they can stay in business here. Have food your customers like your own flavor. Place next door will be a little different. 4 hours up coast to a Jolly Bee's or MC, Donalds from here. Both have a bad burger.