The service I have received from the Guitar Amp and Keyboard centre. I ordered one guitar from them last week, and amazingly I was authorised to use some spare funds here to get a second one (THANKS SQUEEZE first up!!). I ordered a nice looking 7 string and was looking forward to it arriving when I got an email informing me that the guitar I wanted was a new 2014 model and stock wouldn't be in until April. Now, I have waited a LOT longer than that for guitars before. My ESP was an eight month wait for it to be built in their custom shop, and that then became ten when it got bumped back in the queue because one of the big endorsees was going on tour and needed about ten new guitars for the tour. So basically, I would have been happy to wait.
However, GAK emailed me and said they had a very similar guitar in stock but unfortunately it didn't quite meet my specification as it had a Floyd Rose rather than hard-tail bridge. I loved it and said yes please, at which point I realised the alternate was £100 more. GAK gave me the guitar at the same price as my original order, and followed it by pointing out that I now had three guitars and would I like a three guitar stand to keep them all nice and safe, which would be free. Stonking stuff. AND THEN, they paid for immediate FEDEX which means my guitar will be here tomorrow, all at their cost.
Unbelievable customer service, and I will use them for everything guitar-based that I can in future.