Everyone loves a good burger and probably has a go-to favorite that always hits the spot. With so many different types of burger options out there, it's hard to nail down exactly what makes one best in class. Sometimes the best burger is plain and simple, while other times it means topping a prime piece of meat with some over-the-top delicacies. Finding the best burgers in the country isn't an easy task, but we've narrowed it down to some of our favorites that always seem to top the charts in their respective cities. From coast to coast, simple to gourmet, check out our best burgers in the country.

1. 3D Valley Farm Burger

At Holy Grale, a craft beer bar in Louisville, Ky., a fresh pretzel bun adds a new spin to the local beef, which is topped with bacon, caramelized onions, cheddar, arugula and “fritje sauce" — a Dutch-style sauce made with mayonnaise, whole grain mustard and lemon zest. The burgers are paired with double-fried potatoes, and come with lots of different dipping sauce options.

2. Green Chile Cheeseburger

Ask anyone from New Mexico what their favorite food is and the answer will most likely include one main ingredient — green chile. It's no wonder why New Mexicans are so proud of their green chile burgers. At Santa Fe Bite, this particular burger has been crowned the favorite many times over. The green chile is highlighted with just meat, cheese and a bun, all carefully paired to create a mouth-watering meal.

3. Sebastian's Steakhouse Burger

In a city filled with top chefs and their specialty burgers, New York's Brindle Room offers a relatively inexpensive burger that competes alongside some of the most expensive in the city. Only available at lunch, this dry-aged burger features a fatty cut of rib-eye that's cooked in a cast-iron skillet and is topped with cheese, pickles and caramelized onions.

4. L.A. Burger

This L.A. Burger actually stands for Lower Alabama, found in Callaghan Irish Social Club in Mobile, Ala. It's only available at lunchtime and comes in a limited number each day, so it warrants having an early lunch if you are hoping to bite into one. Made with a combo of beef and Conecuh sausage, it's topped with pepper jack cheese, spicy mustard and coleslaw.

5. Old Fashion Burger

Lankford Grocery, a Texas favorite and originally a Depression-era fruit stand, has been serving burgers since the 70's. To this date, this spot makes no claim to ever serving anything small or healthy. The Old Fashion Burger is exactly what it sounds like, served with mayo, mustard, pickle, lettuce, tomato and onion — nothing less, nothing more. It's guaranteed to please.

6. Harry's Bistro Burger

At Abbey Burger Bistro in Baltimore, an Angus patty, applewood bacon, a sunny-side-up egg and cheddar are the main ingredients for this sports bar/bistro's famous burger. The twist here is that it's served on an English muffin, a unique choice and one that makes it stand out from the rest.

7. Mission Burger

Serving a burger at Mission Bowling Club in San Francisco may sound a bit odd, but burgers pair well with bowling. The patties are seared in beef fat, topped with Monterey Jack cheese and caramelized onions, and are served on buns from Acme Bread. It's worth playing a game or two just to try this one.

8. 40-Day Dry Aged Prime Steak Burger

This 40-day dry aged prime steak burger from David Burke Primehouse in Chicago is the most over-the-top of them all. It comes standard with sautéed garlic spinach, crispy fried shallots and bacon mayo. Yes, bacon mayo. Additional toppings that can be added as extras include fried pickles, a fried egg, crab, asparagus hollandaise sauce and super spicy “angry" shrimp.

9. Billionaire Burger

Leave it to Las Vegas to have a burger that means winning big on the slots in order to afford it. At Holsteins, for about double the price of all the other burgers on the menu, the Billionaire Burger is made with Kobe beef, foie gras torchon, port onion marmalade, and topped with frisee and truffle mayonnaise. Make sure to leave room for dessert since this place is also famous for their boozy milkshakes.

10. Beef Burger

Holeman & Finch in Atlanta doesn't have burgers on the menu. But after 9 p.m., Monday through Saturday, customers can try to order one of only 24 burgers in total that are available that night. The owners are all about quality over quantity, and this unusual way to promote an invisible menu item has proven to be successful. The patties are a mixture of grass-fed chuck and brisket and are served with house-made buns, homemade ketchup, mustard and pickles.

May 28 is National Hamburger Day, and there's no better way to celebrate than by biting into a juicy burger. If you happen to be traveling with United and find yourself in one of the above cities, stop in for a burger and find out why they made the cut.