Since everybody is now going crazy over hamburgers in India, here's a rough guide to the broad categories of burger.
The Original Hamburger: Made from ground beef, this is an American staple. A good hamburger used to be made from the cuts that were not good enough for steak, hence the expression: Why have hamburger when you can have steak?
You can still find it at homes and at diners all over America where they make the patty from scratch in the kitchen.
The Fast-Food Hamburger: Said to be perfected by Ray Kroc, the legendary former head of McDonald's, this is a thin, largely-tasteless beef patty which needs lots of sauce to boost its flavour. For a heftier beef-fix, McDonald's created the Big Mac which had two patties, and then most chains jumped in with burgers with larger patties (the quarter-pounder, etc.) but not much taste.
The Mutton Burger: What we usually get in India outside of five-star hotels. The same as the original hamburger but made with mutton (lamb or goat). McDonald's tried it with the Maharaja Mac but failed. Now Burger King is doing a spicy lamb burger with more success. Some mini-chains do good mutton burgers, among them, Café Delhi Heights with the Juicy Lucy Burger.
The Boutique Burger: Hamburgers are all the rage in the US these days and many mini-chains with names like Five Napkin Burger are extremely popular. In the UK, Byron and other chains also exploit this market. Most of them survive on novelty (Kangaroo burgers, new dressings, etc.) but the basic burger patty is made from good-quality beef to justify the higher cost.
The Steakhouse Burger: Most American Steakhouses will sell a high-quality burger made from chopped steak. They claim that you are getting the best cuts of beef, chopped to make a great burger. In the UK, the burger at the Russian-owned Goodman's steakhouse was so popular that the owners built an entirely-new chain (Burger & Lobster) around it.
The Gourmet Burger: Pioneered by the 21 Club in New York but championed by such chefs as Daniel Boulud, this is the steakhouse burger with fancy touches: foie gras, slices of black truffle, etc, can cost the earth.