Sears has some pretty good deals, depending on the sale. They often also just let you drive right in, and they will install the new batteryand dispose of the old battery for free, and then you are ready to go in 15-20 minutes (usually enough time to wander around for a bit). I have had great expereiences with them doing free battery/alternator tests, and even replacing batteries purchased from them, free of charge, if they are not working correctly.
Others' experiences may differ, but I actually have been impressed. I would not say the same thing about their standard service center, but the battery install/check service area has been excellent.
Edit: SP