There are a few systems I've bought special editions for. Usually a nice Pokemon edition will get me to double dip.
Game Boy Color: regular and Pikachu/Pichu edition
N64: regular and Pikachu edition
Game Cube: regular black and Pokemon XD edition
Game Boy Advance SP: NES edition and Pikachu edition
3DS: Pikachu edition, Charizard edition, and Xerneas/Yveltal red edition
And then I had a few PS1s because they had a tendency to stop reading discs.
Bear Bro
The Empire of Silence