There's nothing quite like the Marvel Cinematic Universe. What began with Iron Man in 2008 has blossomed into a rich and detailed series of movies that feel natural in their cohabitation. Created in an attempt reproduce the "all-encompassing" aspect of the Marvel Comic Book Universe, the MCU similarly allows its characters to make appearances over a multitude of interconnected movies, and feel the repercussions of living in a world that shares plot-lines and merges narratives. For most of us, this simply translates as, "OhmyGod, now Thor can fight Captain America," or "OhmyGod, now Tony Stark can team up with the Hulk." It also makes room for a hell of a lot of Samuel L. Jackson cameos. With the MCU in place, though, it's proven to be something of a joy to watch as filmmakers make hints and plant seeds for upcoming story arcs and character developments. For Marvel nerds, it's like eight Christmases in one. Which brings us to the easter eggs, which there have been plenty of. Spotting one of these eggs in the background of a scene or in a layered line of dialogue can often prove itself to be the most rewarding part of any Marvel flick. Chances are you're already well aware that Captain America's shield is visible in Iron Man, or that "The Lonely Man" piano theme can be heard in The Incredible Hulk, so we've tried to dig a little deeper to bring you those easter eggs you probably didn't notice...