There are a lot of privacy coins to choose from. What is "good" entirely depends on each individual's assessment.
Here are some of them:
Pivx
Onion
Cloak
XVG
Grin
Nav
Dash
Monero
From that list, I prefer to choose pivx, xvg, dash, and monero. If you want to search for a low price, then xvg will be a good choice, and you can buy right now as the price is at a low price. But if you want to have the other coins as the investment, then I think you can choose dash, monero, grin too as the investment.