As a G4 collector, I know I want the card and the blind bag pony when I buy them.
If you still have the blind bags figures with respective cards, I personally would keep the cards but that's just me.
In terms of rarity, the only wave of blind bag wave that I would definitely make sure you don't throw out if you have it is the European exclusive blind bag wave, wave 2 (not the wave 2 that came out in the US).