Which of the 5 Avengers Prequels Is the Best?

The movie I have waited my entire life to see arrives in all its IMAX and 3D glory this week. My desire for this movie to happen echoes in the declaration of its director, Joss Whedon, who said at ComicCon, "I have had a dream, all my life, and it was not this good!"

The Avengers is the culmination of years of planning by the folks behind Marvel's modern movie successes. It is what Robert Downey, Jr. said it is: the most ambitious movie I've ever seen.

What makes this movie so fantastic is how they have been able to build up with five different movies, each essentially a prequel to this one. And then they were able to bring the original actors -- with the exception of Ed Norton or Eric Bana for the Hulk -- and put them all in one epic.

Each of those movies stood on their own feet as blockbusters, but some were better than others. Which was the best? Why was one not as good as the others?

Great questions. Let's find out. Starting with the movie that was, ironically, the weakest of the five: