"Since the early 80s, platformers have graced the video game scene. Granted, they weren’t called platformers until long after they appeared, but those early games did define the genre and allow for new and innovative takes on the basic premise of going from one side of the screen to another. While very few of the games on this list are old or genre-defining, the games that I do feature ended up here because of their unique and enjoyable gameplay." Explosion.com
Mario
Sonic
Alex the Kid
Limbo
Donkey Kong
Personally I would have had Rayman Origins in place of it though, that game was brilliant.
DKC and its sequel are amazing platformers. I would probably have super monkey ball in my list if you can class that as a platformer. Anything with monkeys really...
You can't have a top 5 platformers without at least one of the NES Marios.
I'd also remove Mega Man and add Sly 3. DKC would probably be my all-time favorite.