So after a few more weeks of experimentation and trying out some new heroes (Infinite Scholar, Fanatic, Skyscraper, Tempest, Haka, AZ) this is the current quintuplet I've been running:
Team Leader Tachyon, World's Greatest Legacy, Unity(Freedom Six variant), Dark Visionary, Argent Adept.
It gets pretty insane with Adept and his Lyra letting Unity play 2 bots on both WGL's turn and AA's, not to mention her own. And DV keeps the Environment and Villain decks fairly locked down with Premonition, Precognition, Suggestion, and her own power. (And Brain Burn for the Chairman.)
Inculding variants, what do YOU think is the most effective/OP hero quintuplet (in general terms, without knowing which decks they'll be facing)?