Forget BestBuy's in-store. They are usually really expensive.
Go with the manufacturer's warranty, unless BestBuy specifies that it won't accept it back or something.
BestBuy has other brands of HD, but not in SATA. If you have to have SATA, then Maxtor it is. If you can live without it...
Even if your local store doesn't stock the others, you can order through BestBuy's website and have it delivered to your local store for pick-up.