In 2006, a novel cobalt-based superalloy was discovered. Inspired by this unexpected discovery, we performed a first-principles search through 2224 ternary metallic systems of the form X3[A0.5, B0.5], where X = Ni, Co, or Fe, and [A, B] = metals. We found 115 systems that have a smaller decomposition energy and a lower formation enthalpy than the Co3(Al, W) superalloy. They have a stable two-phase equilibrium with the host matrix within the concentration range 0< x <1 (X3[Ax, B1-x]) and have a relative lattice mismatch with the host matrix of less than 7%. These new candidates, narrowed from thousands of possibilities, suggest experimental exploration for new superalloys. Of these 115 systems, 42 have no reported phase diagrams. Based on cost, experimental difficulty, and toxicity, we list the top 10 candidates for further study.  Sato et al., Science 2006; 312 (5770):90-1.  Nyshadham et al., arXiv:1603.05967 (2016).