Hm, most of these look kind of incomplete, honestly. I do like the Faces of the DC Universe covers, especially that beautiful Byrne Wonder Woman one.
I also like the JSA covers Alex Ross did around Infinite Crisis, especially this Captain Marvel one. These had a nice almost chiaroscuro effect going on with the black background and the heavy shadows.
Here’s Jim Lee really doing the white background cover but not for DC… But sort of he is I think this is Wild Storm… I’ll check to see if it’s in our library here.
Green Lantern #62 variant cover. This was originally solicited as a white background cover, but it was changed to a variant with a new background by the time it hit the shelves.