I'm not a huge fan of the more specific pieces at AmApp, I find them to be a little... instead of using the easy, dismissive, vague term "hipster", I'll say the clothes are a bit goofy and childish or immature. I don't have much use for pot leaf snapbacks or mens' tank tops with neck lines that fall below the bellybutton.
HOWEVER, AA is the BEST place to get your basics - high quality, well made, colorful, comfortable and fashionable. I highly recommend their zip ups, their mono-color socks, their extremely comfortable basic t shirts, or their shorts. I'm now totally comfortable with buying a ton of stuff in bulk from AA because I know it will all fit perfectly and look good.