I would say now might be the time to buy some altcoins, tho I would leave lisk and waves alone.
These two were once the hottest in the market as they are the early coins people invested, but although they still have the volume but their development seems to have slowed down.
Eth is a good choice, as I don't think it's going to go down any further. The whole market got slaughtered in 2018, so there are a lot of bargains to be had.
If the altcoins will rally for sure ETH will be the one to lead in the market, so no doubt its a good choice for investors and its currently undervalued now.