The A&F's in the malls around here have extremely loud pop music being played so loud that you can hear the bass 100 meters away. I've never been into one, but from what I've seen when I've passed by it numerous times, the inside is using VERY low lighting, to the point of it being completely dark.

Hm. American Apparel? :P
I dunno much about clothes haha but it's all American made. I have one shirt from them and it's holding up well so far.

Their ads freak the shit out of me.

They would if you're used to A&F ads. ;)

They seem to be out of business =/
anyways, http://www.threadless.com is pretty fun, doubt they'd fit into your category for 'durable' as they're just any other ordinary T'shirts really but the designs are spectacular! :)

My T-Shirts from Dickies are twice as thick as other T-shirts, feel warm but don't feel hot. Work in summer too, the thick fabric for their white T-shirts seem to wick away sweat really well. I get mine at Wal-Mart for decent price, triple that of Hanes shirts but last so much longer. American work-clothes FTW!!!!!
Carhartt is also great stuff, their pants and jackets are sturdy as hell for when I'm cutting wood in winter months but past that I never tried their T-shirts if they have anything.

Nah, they are still open, they just don't sell directly anymore. You have to click through the links and find a retailer.

Threadless uses their own brand and American Apparel according to their FAQ.
Both Design By Humans and Uneetee print on American Apparel.
I prefer DBH's designs over those of Uneetee, but that's personal.
I'm pleased with the shirts I've ordered from both of them.
The shirts held up fine during last year's summer.
You can find several t-shirt sites at teemagnet.com together with discount codes for several of them (like 10% off at DBH).
RIPT Apparel shirts wear down after only a few washes.

Well, thanks, but I'm really looking for shirts. I already have the tees covered :P