I've been to Trader K's twice, and found some great items on the $1 racks, and even scored a Kay Unger gown that was slightly damaged (on the seam, which is easily fixable) for $7.50. I went for the first time yesterday to consign, and I ended up getting some $80 for items I had intended to donate to charity; I was really pleased. And the staff was very friendly to me. I will definitely be back again soon to consign!
Pros: $1 rack before you even get in the store!
Cons: Location (1hr north of my hometown)