In Canada they're called Value Village and are usually much bigger than other thrift stores. They're also usually a tad more expensive, but they're worth checking out. I'd budget at least an hour and a half to two hours to go through one thoroughly.

We have a Savers here in Austin. I like it! I think ours is in a good area because there are always designer things there. We've found DVF, nice AT, BR, BCBG, JCrew etc things there.
What I like is that if you bring a bag of items to donate, you get a 20% off coupon. We always puruse the books and music as well. We've come away with some classic U2, The Cranberries, old Nancy Drews (a childhood favorite), and so on. Fun store. :)

I love Savers. I shop there very often. I too have found many name brand items. I donate my stuff there too. What is interesting is that in the donation area which is behind the store, they will have pallets of clothes all bound together, like they are going to be put into inventory. I think they must get items from other parts of the country, not just locally.

I also agree that you have to allow enough time to really browse the racks. It is also helpful if hubby and/or kids are not standing by waiting for you!

Susan D