Opinions are like A _ _ H _ _ _ _ ! Everybody has one. I have no idea what part of the country you reside. If per chance you are reasonably close to a quality audio dealer that carries several brands of integrated amps, in the price range mentioned, I suggest spending a day listening to everything he has with different loudspeakers. You should walk away with a better understanding and audible opinion of what truly sounds best to you.
My personal opinion, (yes I have one too ) would be the the PASS INT-60 paired with MAGNEPAN 3.7i. If that doesn't take you to a completely different world of audio reproduction and appreciation, I don't know what will.. The whole package will be a bit beyond your budget, but the end result will be worth it. It's a system that you could live with for many many years.