I'm based in Europe, had really great support from Lenovo, and the best service ever from XMG.
For USA I highly doubt you will find anyone that can compare with Apple. And honestly, I never trusted those graphs like
@maflynn posted. On reddit there are loads of complaints about Razer for example. And I do mean lots of those. Even when compared to macrumors and MBP complaints.
But then again, I could be mistaken. But that fact alone keeps me away from Razer.
Problem with support in general is that it varies country by country. For example, Lenovo has great international support. Not as good as Apple, but really close. HP had that before, and they are still good enough in my own country. But in other countries they are rather poor. For Dell I can't speak, never had to deal with them in the past.