Down in the Valley has been a Golden Valley institution for many years, but I usually shop the Crystal location.
If you are looking for ANY kind of music - new or used- they have it. Seriously. I just purchased a CD from a Finnish metal band for myself - not something you would find at Sam Goodies or Best Buy. They have a very extensive selection of Classical, Blues, Jazz and World Music. If they don't have it in store you are certain to find it in their online shop.
They also have a HUGE selection of funky gifts, books, and clothes to suit most people. They now also have a VIP club card that saves you $1.00 off any CD/DVD/Game and 5% off everything else.
As far as pricing, you will find the newest Top 40 CD's at Target for less - that's a given. But if you have a diverse taste in music you need to check Down in the Valley out.