Surprisingly, I couldn't find a thread on this specific subject. The topic comes up in many threads but it doesn't appear to have a thread devoted to it.
What are your favorite complementary plastics, especially if this allows you to bag multiples of the same mold? I'm thinking of answers like "Champion for an overstable bookend + cycling DX" or "Star + Pro for overstable and understable."
To answer my own question --
Biofuzion and Lucid-X.
Lucid-X provides that extra tick and half of overstability compared to the 'normal' DD premium plastics (Fuzion and Lucid) plus is indestructible. Biofuzion does the opposite, as it beats in quickly but still has the same feel as regular Fuzion. Lucid-X + Biofuzion makes the perfect pairing, and is one I use for multiple molds in my bag.