Which audio companies have you found to have the greatest customer service? Any that you avoid... and if so, why?

I'll go first: Pass Labs, VAC, Martinlogan, REL, SVS, basically just incredible and love to talk about their gear and help you out whether you're buying new or used from a private party. I went with a Holo DAC that is fantastic, but the customer service was a bit tricky compared with the others. No quick/easy phone pickup with an enthusiastic expert like the others.