I think you forgot PirateCoin (ARRR). The coin is still relatively young compared to those listed, but has the strongest privacy functions in the crypto universe so far. In the past I used Monero as well, but now PirateCoin is my favorite privacy coin. You can found more information here https://pirate.black . The coin recently increased from $0.3 to over $5, but is now back at around $2.5. But still a big decreasing. You should definitely watch the coin 
PirateCoin was pumped in my surprise 2 months ago. I know it but I don't believe much about that coin. Grin, Beam are better for me. I could be wrong. Correct me if Pirate coin has better technology than Beam or Grin.I think Monero has a role as same as Ethereum for altcoins and ERC20 tokens. Other privacy coins will rely on Monero leadership. When Monero rises and doubles its price, smaller privacy coins will be on their rocket boosters.