The X Games have brought more mainstream attention to extreme sports over the last 17 years in a way that no other event could. Every summer (and winter) ESPN dedicates a certain number of hours over the span of 3-5 days, and shows the best skateboarders, BMX riders, motorcycle riders, etc. competing in a wide range of events that showcase an individual's skills.
What has slowly become the marquee event of the Games is the Moto X Best Trick competition (formerly known as Moto X Big Air), in which the best motocross riders in the world are given 2 attempts to take off from a dirt covered ramp that usually sends them more than 60 feet in the air. A panel of judges who are never shown on camera evaluates the style, trick difficulty, and originality of the jump, scoring each jump on a 100-point scale. Each rider's highest single-jump score is the one that is used. Best score wins gold.
Here's an explanation on the evolution of the Best Trick competition, and 3 never before-landed tricks that, if landed, would change Moto X Freestyle riding forever: