poweramps
An endangered species - because iIntegrated amplifiers are becoming quite good - but any audiophile will tell you that the best sounding hi-fi systems will have each component be separate, because that ensures that no component can interfere or add distortion to another. For this reason, hi-fi juggernauts like Constellation Audio, Moon, Michi, Rotel and NAD Electronics still make dedicated power amplifiers that you can buy.
The problem is that they tend to cost a lot because they're meant for a high-end hi-fi system, usually to drive big and expensive speakers. If you're looking for a more affordable option, Rotel and NAD make excellent stand-alone power amplifiers.