If you want to mine and hold I would suggest looking for newer coins with lower difficulty.  Check whattomine on a daily basis adjust your miners as necessary.
Don't put all your eggs in one basket.  Diversify and hold.
Currently you can mine quite a bit of ETN.  There is a lot of hype around this coin.  Predictions anywhere from $1 to $30 in years to come.  Either way it might not be a bad idea to mine around 1000 of each new coin and hold for a year or two.  If you mined 1,000 of each new coin you never know- could end up hitting the jackpot.

Staple coins seem to be Eth, Monero, Zcash.  But you may want to hold some Bitcoin gold as well.