Couple more, some from the Smash Wiki that are probably just bunk theories:
Bowser 4 looks like Super Mario World Bowser, Bowser 5 Dry Bowser. Bowser 7, IMO, brings to mind Midbus, but that's probably a coincidence. Bowser 8 looked like Original Art Bowser, but doesn't in Smash 4.
Charizard 6 looks like Aerodactyl a lot. It's rather surprising.
Luigi: 5 looks like Mario on the American cover to Mario Bros. A bit obscure, but it does look like it. The dupe default was an error in the magazine, for what it's worht. The real costume is some yellow shirt with blue overalls.
Mario: 3 looks like the Mario Bros. boxart we all went over in the Brawl days,
Ness The tiled one here is a reference to the file select and character naming screens in EarthBound, same that got homaged with Yoyo Kirby.
Olimar: Alph's green and pink are Charlie and Brittany from Pikmin 3.