GT440 here with J River Media Center 17. As previously posted, leave the settings at the default neutral settings. The only thing I did in the Nvidia driver is set scaling for the desktop to eliminate overscan when displaying the MC browser. I am using the Red October HQ HW accelerated setting in MC (MadVR and LAV) and the only settings in MadVR I have changed are the upscaling values (for SD DVD playback) and I adjusted the gamma from 2.20 to 2.15 to match the picture from my Oppo BDP-83.
I play MKV's exclusively - feature rips from BD's and DVD's.
Emotiva XMC-1 & XPA-5, B&W CM9s2, CM8s2, CMC, Hsu VTF-15, Sony BDP-S790 & HX929, Auralic Aries, Apple TV