I buy my clothes at Goodwill and at LL Bean.
I buy khakis because they're more comfortable than jeans and they count as business casual and polos because they aren't as clingy as female shirts tend to be plus they count as business casual. I love tech fabrics, and after purchasing my first tagless shirt years ago, there's no way I'll ever go back.
GW is great near me. Some of them have an intense smell from whatever detergent they use, but the one near me has great ventilation. It's in "the good part of town," which means I see a lot of Land's End, LL Bean, Banana Republic, North face, etc. If you go at the right times on the right days, there aren't a lot of people. The stores don't tend to be brightly lit, which a lot of people complain about, but I've never had any trouble seeing flaws. A lot of stuff there was either worn once, never worn (as in still has the tags on it), or was sent to the dry cleaners and never retrieved. I've bought nice cashmere sweaters and silk lined peacoats there, as well as a telescope to stare at the stars, a lot of cds, dvds, an e-reader, fishing gear, and piles of books.
Downsides: if you go on the wrong day/at the wrong time, it can be full of families with kids. This is sadly especially true on half off Saturdays when it becomes a mob scene. If you want to take advantage of half off Saturdays, you have to either go really early or really late. Really early is of course more preferable because you have more selection.
If you go to one that isn't in "the good part of town," expect the quality of what's available to suffer.
Also, like I said before, some of them smell very strongly of that detergent they use.