Best Standard Def DVD Player under $8,000 used?

I am looking for the best possible Standard Def DVD player
that is BLACK. I have a Krell DVD Showcase now and it's
great but I am wondering if there is better to be had for
under $8,000 used.

I would like to hear opinions/comparisons of the video
quality for:

Krell DVD Standard
Linn Unidisk 1.1
Meridian G98
Denon 5910CI

Thanks
Tom