I thought this quote from a movie review was great.
"Q: What is the best thing about The Avengers?
A: Robert Downey Jr. is the best thing in The Avengers. Though, I feel we’re getting to the point that if the question were, “What’s the best thing about living on Earth?” the answer would still be “Robert Downey Jr."
I included the review of Avengers, but there are some spoilers so warning before you click the link