ETHereum is the only real chain. ETC (Etc Troll Coin) is dead snake skin worn by bitcoin maxers desperate to suppress ETH by creating FUD. Reminds me of the GOP and Donald Trumps campaign.
Long term, development drives gains in the upward direction. ETHereum development is through the roof right now and some really amazing applications on the horizon. DEVCON2 in Shanghai, China also coming this Fall. :)