I've had to deal with the customer service desk at Best Buy Store #694 in SE Aurora, CO on four occasions since it opened (about 3 years ago). I have to say, I'm very happy with them.
The first time was when I had to exchange an Xbox 360 that was giving me the infamous "red ring of death". Since this was before Microsoft had owned up to their hardware failures and started fixing problems after 3 months, I decided to invoke the Best Buy product replacement plan. Took the box to the desk, they brought me a new one. I asked if I could keep my old hard drive, and they said it would be no problem. (It was a common request by this point.) They helped me unpack the new console and swap hard drives. Aside from time spent in line, I was in and out in probably 10 minutes.
The second time, I had ordered a game from BestBuy.com, and when it was finally delivered (UPS mis-routed it first, and then severe snowstorms prevented its final delivery another week), it ended up being the wrong game. I brought it to the customer service desk, and the gal working there explained that Best Buy stores and BestBuy.com were separate entities, so they were limited to what they could do. They checked to see if they had the game I wanted in stock, but they didn't (which was why I ordered online in the first place), so she said I'd have to deal with BestBuy.com's customer support. She then picked up the phone and called BestBuy.com's customer support, explained the situation, and turned the phone over to me so I could finish the details. She could've very easily just told me to go home and call them, but the fact that she took an interest in getting me in touch with whom I needed to talk to, to get my issue resolved, really went a long way to winning my respect.
The third issue was when we had just picked up a business points membership or some such promotion. We bought a couple items, and we were supposed to get a certain amount discounted. The register refused to give us the appropriate discount, and the cashier wasn't able to do much about it. (Not surprising. I've been a cashier, albeit in a grocery store, and for better or worse, you're given very little control.) She directed us to customer service. We took our receipt over, and the gal there worked with the register for a bit. Then fought with it. She wasn't able to get it to give us the precise amount of credit back on our credit card, but she figured out a way to coerce the register to give us a discount that resulted in a slightly higher amount (like a buck and a half), so she went with that and called it good. All the while, she had a very positive attitude about helping, even when the system was obviously frustrating.
And then comes the most recent experience. I figured this one might be the most... interesting. Once again, I had an Xbox 360 that needed replacing. Because the hard drive sizes had been increased, I figured this time, I didn't want to just keep my old hard drive; I'd want to transfer my data from the old drive to the new. I'd done the research to see what it would take and invoked the GeezerGamers.com network to obtain a hard drive transfer kit that Microsoft provides for this purpose. I entered the store, armed with the transfer kit and some fresh Krispy Kreme donuts for bribery.
Once I had selected my replacement system (a 360 Elite, which, since the Best Buy replacement plan is based on original purchase price and the console prices had dropped quite a bit, only cost me the price of a new replacement plan if I wanted it -- "You better believe it" was my reply to that), I explained what I wanted to do. I explained that I had the transfer kit with me, and donuts. She politely declined the donuts (saying that, oddly enough, I was the third person to offer her donuts that day) and asked what I would need. Just a TV, and I made a point of saying it would probably take an hour. (I figured it was only fair that she knew exactly what I was asking.) As it so happened, the Geek Squad desk around the corner had a TV monitor that they rarely use, and they were happy to let me use it. They couldn't assist with the actual transfer (a policy that comes from wanting to avoid getting into legal tangles transferring songs between MP3 players), which I understood completely. About an hour later, I handed her the old hard drive, thanked her again, again offered her donuts (which she again politely declined), and walked out with my shiny new Elite.
So I just have to give "mad props" to this store's customer service team. They've really helped me out. I'm not saying I'd expect them to break rules for me, though — before helping me, the gal (who is likely a customer service manager, which is probably why she was able to get me set up on a TV for an hour) had to be called over to explain to someone else that they can't price-match another store's bundle deal. But as far as helping me out with issues, they've been nice, friendly, willing to help, and willing to do what it takes to resolve whatever problem I've had.