IMHO, ASRock have got to be bottom of the list - Completely refusing to honor warranties for faulty products and up to two weeks to respond to tech support tickets, if they respond at all. Fine, they are an Asian manufacturer, but if you are going to sell to English speaking customers, it would be helpful if you had support staff who had some understanding of English. I've found myself having to explain things to them many times.
MSI would be close to ASRock. Their support website and forums are atrocious, with posting questions and replies a real hit and miss affair. MSI staff are belligerent, unresponsive and quick to blame everything on any one but themselves. Also find it difficult to support English speaking customers.
But lets not forget ASUS, the over-priced under-featured manufacturer. I've never had/supplied an ASUS product that worked as it should. And woe be you if you look for customer service or technical support. Quick to fob you off, unresponsive, slow to process RMAs and a web site that's as bad as their attitude towards customers. Their promotions sometimes aren't above board either. ASUS love to brag about how good their support experience is - Not even close to true.
Seagate on the other hand has always been easy to deal with, though their support website can get stuck in loops at times.
I've not had to test out Razer, I've never had one of their products fail (Mice, laptop and headsets)