I think you will find that Denon and HK are the most popular, probably followed by Onkyo and Rotel, then an increasingly small number of other brands.

There used to be a poll on this, I think, although not M60-specific. Does anyone remember where it is ?

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8