A music, book and video store. The first one opened up in Sacramento, California in 1960 on Watt Ave. Now there are over 180 stores worldwide.
I like Tower. You can't really consider them independents anymore, but the stores all seem to have enough autonomy with purchasing so that it's not too boring to shop there.
My local Tower is in Mountain View. It's got a pretty good alternative cultures section in the book store.
On the web at http://www.towerrecords.com .