When you have to grind in two games, might as well double up the fun

Leafgreen and Soulsilver. Leafgreen taking the time to level up a bunch of Pokémon to levels 40-45 depending on whether I am holding their evolutions for moves not learned until after level 40, before working on gyms 5-7. Soulsilver, I wanna do another run through of HG, but the party I wanna run with requires one of the gift Pokémon from after beating Red, so hitting the E4 over and over.