I have access to a "SHIT-LOAD" of power to mine,
and want to get back into the cryptocurrency business...

How to find out what "Altcoins" have a market? (a market, in terms of, are worth to mine and aren't a struggle to get exchanged into BTC afterwards)

What I look for in an altcoin:
>a market: SELLING the coin for Bitcoins/PayPal isn't a struggle...
>mining difficulty: The difficulty shouldn't be something like Litecoins, for example, what is basically considered a waste of power/time (you get me)

How to find out if an altcoin has a market // whether or not it is worth to mine it. Looking for experienced people to tell me where I can find answers to those questions.