Referencing an earlier post of mine because it's relevant here. The 480p one is the Wii native res, followed by approximations at 720 and 1080p.
The bottom three are with anti-aliasing. I really really really wish more games used AA @ 720p as the jaggies are still noticeable (Mario Kart 8, I'm looking at you, though 2xAF would have helped, though it's not as noticeable as the jaggies):
The 480p-720p gap is a lot more prominent than 720p-1080p to my eyes.
Regarding 720p + AA, games like Mario 3D World and Captain Toad achieve fairly nice image quality in this way.