I like best buy, I think this is one of the best places to purchase electronics. I like the to purchase at the best price, so generally I end up purchasing online, at best buy or at Fry's. I like to shop at Best Buy since they tend to have a good selection and the store is set up to be like a store rather than a warehouse like Fry's.
The Best Buy at Santana Row is small and has very little space. They have an escalator in order to fit all the merchandise they sell and be able to display it. They do sell out often, but you could go to Milpitas if you reallt needed it. Go online and use their inventory search in order to be sure your item is at this location before fighting the parking lot.
This best buy is in the best location (before the sunnyvale one opens). It is next to Valley Fair as well so you can shop for your electronics after your shop for your clothes. Or you could drop off dad and brother before going to valley fair. But it is too small to consistantly know you