The "365" brand that Whole Foods sells is pretty good and moderately priced.
There is a imported brand that Williams and Sonoma sells called Guisti (I think that's how it is spelled.) Anyway, WS wanted $20 a bottle for it last I saw. I was in a local supermarket in Modena a few years ago and they sell the same stuff as an every day vinegar for about $3 a bottle. Just goes to show, you can take a fancy bottle with the label written in Italian and grossly over charge. Ain't capitalism wonderful?