for aftermarket products Rockford Fosgate has arguably some of the best products.
back in HS I had the "boom boom" system, RF subs, and the loudest in the whole school, and it was cheaper by hundreds $$ than other systems.
my favorite current factory system is the cadillac bose, but I always hoped Rockford Fosgate would get into that market, or at least full sound systems.
I don't want a stereo that vibrates the car, just full sound clear and even, and you can't do that without a lot of power and solid sound cones.