Burgers are a staple in the U.S.; and if you own a "Burger Joint", you will inherently have a tremendous amount of competition. Americans typically like the burger recipe the way it is, and has been for years: grilled or broiled patty, with those regular condiments (lettuce, tomatoes, ketchup, pickles, mustard, etc.). So changing this, and making it beloved by consumers may be tricky. Here's an idea, and easier way for your "joint" to stand out: provide an original side. How about uplifting that typical burger side...the french fry. Imagine something like a "Fry Bar" wherein customers have a variety of toppings to change the flavor of the fries to their liking (spices should be a staple, as many can keep for several years, help in keeping overhead down, and offer the greatest variety of flavors - plus, have you tried garlic salt on fries?....YUMMY.) Test recipes and give suggestions to customers on how much to use and what to mix (based on a recipe board). If thought out, and marketed right, this is a nice novelty that could generate needed interest, especially with new customers. And, as long as your burgers and fries (without the bar) can compete with other establishments, than this could be the way your "Joint" stands out.
"Pizza Joint's" are also common in the U.S.. We all love pizza, and in most opinions there are three main ingredients that affect the overall taste: the cheese, the crust, and the sauce (though tasty, toppings can be similar at many restaurants). To stand out, take one of these key ingredients and make it a focal point in your restaurant (to a degree that your "joint's" name becomes synonymous with that ingredient). Here's an idea: spend a significant amount of time developing the perfect variety of incredible sauces for your pizzas. Consider creating several marinara's (spicy, sweet, etc.) a perfectly flavored white sauce, a unique barbecue sauce, pesto sauce, even a couple novelty sauces that your competition would never even consider (cajun, clam sauce, etc. etc.). Then, include in your menu an appetizer sampler that incorporates these sauces with some corresponding food (breadsticks, vegetables, wings, etc.). This allows customers to not only get an impression of your "joint's" focus on such a key ingredient, but also an idea of what type of pizza they might like. Offer them a discount on their pizza order, if they sample taste and give you a review of each sauce (a simple statement that should add some incentive for them to be sincere with their opinions, and helps you understand what works according to the flavor palette of people in the area). This novel and fun approach, along with your attention to a such key ingredient and customers opinions, could help you stand out amongst that overwhelming competition.