Hmmm let's think...

Best/Worst on the eiter side of the slash...

C64 (if limiting it to cartridges): Myth/Close Encounters
C64 (any game): The Sentinel/Robobolt
Vic20 (cart): Jelly Monsters/Artillery Duel
NES: Super Mario Bros 3/Where's Waldo?
SNES: Super Mario Kart/Home Alone
N64: Zelda:OoT/Superman
GC: Metroid Prime/Batman Dark Tomorrow
GB: Metroid II/Home Alone (I don't think ANY version was good!)
GBA: Wario Ware/Powerpuff Girls
NGPC: Cardfighters Clash/Neo Dragon's Wild
Vectrex: Protector/Polar Rescue
Atari 2600: Thrust/Snakes
Atari 7800: Joust/Meltdown
Atari Jaguar: Tempest 2000/Cybermorph (didn't like it at all)