Streetfighter backgrounds are pretty boring compared to the SNK stuff IMO.
dunno. i think SNK backgrounds at some point really started feeling like "what else can we fit there to make things more busy and interesting ?"
Plus, while i do generally find SNK's "concepts" for backgrounds more interesting, i like Capcom's execution and pixelart much better.
There is a difference; a lot of what Capcom artists achieved was basically optical illusions, using colors in a way that pixels would look smaller than what they actually were, or simply "hinting" at sub pixel details that you'd see but were not actually there.
They paid a lot of attention to aesthetics, avoided using black or too much contrast to hide jaggies or pixelated look.
Capcom artists were faking a higher resolution, sometimes wasting one of the few colors available for sprites only to do some sort of manual anti-alias and make things appear smoother.
Their pixel technique is unmatched, and their games all had a very unique look.
SNK's execution on the contrary is very straightforward.
They were not shy of using black or high contrast, didn't rely on subtlety and in the arcades, their backgrounds appeared very pixelated and rougher, which made them a lot less attractive than these small gifs.