Check out the Marantz M-CR510. I bought one and have been blown away at how good it sounds for the money. You can get it for $499. The feature set is what causes the unit to stand out with built in Spotify, Pandora, Digital Radio, AirPlay via onboard wireless along with it being UPnP and DLNA compliant.

The DAC implementation is outstanding and the Class D amplifier is detailed without a hint of brightness. A poster in the WhatHiFi forums replaced his PM6004 with it and said it sounds exactly the same which is pretty high praise as that Marantz PM6004 was considered outstanding for the money. I believe him as this unit has way outperformed my expectations.

The only criticism I can think of is that Marantz was pretty liberal in the 60w power rating as it is publishing the 6 ohm rating and really delivers 40w into 8 ohms, or 10w more than the NAD.

Also, I have listened to the D 3020 and it is awesome. I would say that in sound quality, it is every bit as clear as the C326BEE but is a hair more neutral. I feel the 326BEE is a bit warmer than Marantz. It is an impressive unit.

The only issue I have with it is the feature set which includes Bluetooth and basically nothing else. NAD produces outstanding quality amplifiers that sound amazing but with limited functionality. Marantz produces outstanding quality amplifiers with great functionality. Here is the review from audioholics of it and the sister unit M-CR610.

http://www.audioholics.com/av-receiver-reviews/marantz-m-cr510-m-cr610-wireless-receivers

Also, if you look in Class C recommended components the M-CR610 and the NAD D 3020 are both recommended. The M-CR510 lacks the CD player and a second analog input compared to the CR610 with the same amplification unit.

Other notes - I do not like the sound of Yamaha integrated amps. I feel like they are bright and lack detail compared to NAD or Marantz. Denon and Marantz are owned by the same company but have different sounds. Marantz tends to be a hair warm while Denon is more neutral. For a traditional integrated, you might also consider a Music Hall 15.3a.