I have recently had both some spectacularly good customer service, and some really quite poor service. In a great example of "you get what you pay for", the bad service was from Vodafone, to whom I pay a chunk of money every month, and the good service was from Sourceforge, who I pay exactly nothing.
Since my mobile contract with O2 ran out just over a month ago, I've been trying to find a better provider. First, I tried T-mobile. They were cheap, and while their coverage was no better than O2's (and that's why I left O2 in the first place) I don't really mind when they charge only a third of the price. However, I couldn't stay with T-mobile, because of their appallingly bad software. Someone sent me an MMS, which T-mobile notified me of, inviting me to go to a webshite to look at the image. That webshite chastised me for not using IE6, a decade old web browser which only works on Windows. In particular, it doesn't work on mobile phones. You know, the platform T-mobile's customers use. In fact, that website didn't work with any of the four browsers I tried on three platforms, and the message was lost. So fuck T-mobile, with a pineaple. I lasted ten days with them before firing them for gross incompetence, and switched to Vodafone.
Unfortunately, Vodafone haven't exactly pleased me either. For some bizarre reason they saw fit to censor my web access from my phone, and to charge me for the privelege of turning the censor off. I grudgingly paid up (it was only a quid) only to receive a text message with words to the effect of "the censor has been turned on, your web access will now be filtered". One quick call to customer services and it was fixed, the phone-drone (who was actually quite helpful) telling me that this was a common problem, because the wording on their website was wrong. So, it's a known problem, but they can't be arsed to fix it. They also failed to notify me when someone left me a voicemail, so I picked up an important message several days late, and despite me specifically buying a tariff for iPhone users, visual voicemail doesn't work. When I emailed them to ask them to sort it out, I got what is obviously a canned answer to a vaguely related question, but not actually what I wanted. If they can't fix that tomorrow, I'm firing Vodafone too. Trouble is, I'm running out of alternatives. Any suggestions? Must have excellent 3G coverage in London, excellent voice coverage nationwide, and usable (if slow) data coverage in Ruralistan. Must support the iPhone's shiny features. Must not be T-mobile beause they're incompetent cunts.
As for Sourceforge, they recently had a bit of a problem with naughty people trying to break in to their systems. They proactively spotted the problem. They notified all their users. When I emailed them with a query I got a personal response within a couple of hours, pointing me at a couple of webpages which they were keeping updated with status reports. That's good customer service. Fixing the customer's problem isn't actually the most important bit of customer service (Sourceforge still haven't fixed everything a week later) - the most important bit of customer service is communication. Communicate quickly and clearly and customers will put up with an awful lot.
And also I should give Apple an honorary mention. I went into their shop yesterday (and damnit, it's a shop, not a store), and was served by a Sikh gentleman with a Magnificent Beard. Hurrah!