I'm known to have a pretty good ear for music and audio. I've mixed bands live in a professional setting for years. Modern amplifiers are so clean now adays, that normal or even discerning person can't tell a difference. There was a double-blind study done (I can't find the link at the momemt) that used the same high end speakers, but changed out the amplifier and CD player. Most of the 'golden ears' couldn't tell the difference between the crappy amp and the reference amp, and a bunch preferred the crappy amp over the reference amp without knowing what they were choosing.
I'm perfectly happy with my sub $300 Yamaha receiver and my Paradigm's. They sound fantastic.
As long as you don't push your amplifier to the point where it adds distortion, or starts clipping, any amplifier will do. Spend your money on good speakers.