Hi Mike82,
I have been a fan of the cryogenically-treated Hubbell Specification Grade Heavy Duty 5362 receptacles. They have a high copper content brass that are super high quality. Another reasonably priced alternative is the cryogenically treated Pass & Seymour Industrial Specification Grade 5362 receptacle.
If you want "state of the art" with the price tag to boot, get the Furutech GTX-D (Gold) receptacles, a very fine choice.
I have been told by my audiophile customers that the cryogenically treated Hubbell IG8300 receptacle synergizes very well with my power cords as well, but I have not tried them...
Cheers,
Pete