Personally, I think Achilles did the right thing in not fighting. Agamemnon was simply asking for problems with his Hubris.
Didn't the legends say something about Achilles having a choice between going to war and dying but being remembered forever, and not going to war, living a long and happy live with a family, but being forgotten to history?
I think that was just a fabrication in the movie, to add some dramatic tension. It seemed to me a bit out of places for the minor roll Achilles had.
I just re read my copy of The Hektoriad, and I was wrong in my first post... he did go to war, but left before things really got started because of the fight with Agamemnon. But it doesn't mention him being given a choice. Then again, the story is by a Trojan poet, so what would he know/care what Achilles did?