What companies do you admire for their user/customer support?

Support experience can make or break a product experience for users. I think there's a lot you can glance about a company/product's trajectory by looking at how their support functions, especially for startups looking to kick some incumbents by embellishing support as a key differentiator in their offerings.

I think there's a lot to unpack in the nitty-gritty - would love to hear HN's thoughts on companies they've seen doing this well -- big or small, a brand name or unknown, ...