I'm not counting platform shoot-em-ups like Turrican or Super Metroid here.
MSX: King's Valley
c64: giana sisters
Amiga: Lost Vikings, Blues Brothers, Chuck Rock... very tough choice
PC: Claw by Monolith (possibly the last 2d platform game released on the pc?)
GB: mario land 2
GBA: dunno. Haven't played a NEW platform game on it yet.
NES: mario 1
SNES: super mario world, 2 player game through zsnes netplay
sega: sonic 1
N64: tough choice between Super Mario 64 and Banjo Tooie
Atari 2600: some pac-man like game with a bear. Can't remember the name.
Playstation 1: Crash Bandicoot 2
Playstation 2: Jak & Daxter
Don't think I played games on other systems...