How I Met Your Mother Episode 4.02 The Best Burger in New York

When Marshall reminisces about finding the best burger his first night in New York but not being able to find the restaurant since then, the gang sets out on a mission to find the legendary burger. But as the search grows futile, Marshall becomes overly fixated in finding the burger, making the gang question if this has more to do with him not being able to find a job and the toll it's taking on him.