If you want perfect balance, play Chess or Go.
If you want something sci-fi themed, miniatures-based, and grimdark and close to balance, then WH40k is usually pretty good for the first two, maybe two-and-a-half, years after a new edition drops.
If you want something sci-fi themed, miniatures-based, and grimdark and much closer to balance, throughout its entire edition life, then you should play BattleTech.