Because you like Rob Hawkins in Cloverfield

He tells you everything you need to know: "I. Am. Groot." See them in Marvel Cinematic Universe.

With his own ship, Peter Quill calls his own shots, and gets to fly from planet to planet blasting '70s pop hits and picking up alien chicks. See them in Marvel Cinematic Universe.

Tony Stark's interests include cocktails, beautiful women, particle physics, and saving the world. See them in Marvel Cinematic Universe.

With great power comes great responsibility, but Peter Parker always seems to get the short end of that bargain. See them in Marvel Cinematic Universe.