No love for the Denons?
Actually...between the three you've listed, I think my personal preference might be the Pioneer...solely because I've had good luck with all of my Pioneer equipment.
I hear good things about Marantz in general and Onkyo seems like a pretty solid brand as well...although I've read that the 805 runs a bit on the warm side if that's any consideration.
Have you tried popping over to the Axiom forums to see what people there think about how they mate with your speakers? Might be worth a shot...they may be able to stter you away from any undesirable combos.