Evolution: SAMUS (Smash Files 17)
In the original game, the design of Samus was based off of her Varia suit in Super Metroid. The original Super Smash Bros. was also the first and only time Samus appeared on the N64, as well as her first appearance in 3D. She was also arguably the only female character in the game (depending on the gender you give to Pikachu and Jigglypuff... and Yoshi....) Of note: her blaster in the artwork on the left is gray, rather than green.
In Melee the suit Samus wore once again resembled the Varia suit; Melee was her first appearance on the Gamecube and her second appearance in 3D. Her blaster here is a more muddy sort of green than before. Like the rest of the Melee cast, her promo artwork has one stripe (in this case gray) and one block (...dark blue? Purple? Violet? Navy? What the heck shade is that, anyway?)
Her blaster here is back to a more regular green shade, but it is now also metallic (as it should be). Brawl added many details to the armor of Samus not present before, such as the assorted light details and the gleam of light on her power armor. Again, the armor takes inspiration from the Varia suit.
Brawl also introduced Zero Suit Samus to the mix; Zero Suit Samus could be used after Samus completed her final smash. ZS Samus has a blue body suit, and of course that wicked cool pistol that turns into that weird energy whip thing.
In a stunning turn of events, in the new game the power suit Samus uses is her regular suit from Metroid: Other M, rather than being based off of her Varia suit like the last three installments. Also, her blaster is now turqoise with bright green highlights, rather than be a shade of regular old green. Her Other M look is also far smoother than her Brawl look. I approve.
And of course, Samus in the 3DS version. She looks pretty cool. Again, the comic book graphics are awesome, but Samus doesn't feel like she's a part of the stage here - more like something out of a pop-up book.