Space Kaijuu said:

I used to have this version: http://www.amazon.com/dp/6305078955/

A closer inspection of the The Complete Superman Collection -- Diamond Anniversary Edition (2000) package shows "DVD package design ©MM Image® Entertainment Inc.", while "program content and artwork ©1991 Bosko Video".

With your version, The Superman Cartoons Of Max & Dave Fleischer (1998), the package also has different credits between content and packaging (hard to resolve the blurry Amazon package picture to be more specific).

It may be both of these were simple repackaging of the same original content (verifiable with screen-caps from the older one).

Also, in the process of looking this up, I came across ImageFX's article Fleischer's Superman lands on YouTube http://beta.imaginefx.com/fleischers-superman-lands-youtube-61128. Warner Bros. posted on YouTube these first nine episodes of their DVD release -- up to 480p and with very good video quality (like the above posted samples!):
https://www.youtube.com/user/WarnerBrosOnline/search?query=fleischer
Thanks, WB! But, as davextreme noted, they are flawed and need fixing.