Tirerack.com maintains a list of recommended installers. I went to a Midas shop they recommended and the service and quality of work was fantastic! Since then I have had two sets of tires put on our van as well and every time the work was first class. I can't speak about other shops they recommend but I would trust their recommendation; Here's the link:

http://www.tirerack.com/installer/index.jsp


I've heard good things about Discount tire as well.