I have a best buy near work that I have used to get replacement DVD drives and video cards when one of the computers I support fails. I would rather go to Micro Center, but the trip there is a little bit longer. I have never been too impressed with the knowledge of the sales staff, but I don't have any major gripe about BB.
I am lucky in that there is a great store in my area - Keeble and Shuchat in Palo Alto. Their prices are beatable online, but they have seemingly everything in stock, they have some of the most knowledgeable people around, I have never encountered "attitude" there, and they run a lot of classes and workshops. I prefer to shop locally if possible, and I would much rather go to a specialty store than a big box place. (I refuse to step foot into Wally Mart.)
There used to be a nice Mom and Pop camera store in Mountain View, and I remember buying lots of things at Denevi Camera. Good thing I don't live next to Adorama or B&H!