My research shows both brands are questionable, but alas, I refuxe to buy from a sexist pig, being that I am female. Both seem to provide hostile anti union work environments.
MisFortune 500 Company American Apparel Ads: Sexy Or Sexist? Infoshop News - American Apparel: Anti-Union & Sexist
And lookee here, I got a hit for "Gildan sweatshop"
LA REVUE GAUCHE - Left Analysis And Comment: Gildan Sweat Shop Success Story
this article is a bit newer
T-Shirt Sweatshops: Central America Exploited
I really like Continental, what is the word on their labor ethics? Ah ha I found an article comparing AA to Continental on this very topic:
Roots of Compassion » Blog Archive » CONTINENTAL CLOTHING vs american apparel
Enjoy and please share any further information