There are none of them as good as Proton.

For example, AirVPN hasn’t had any security audits and doesn’t seem too interested in them either due to monetary concerns. That’s a deal breaker for me.

Mullvad (or Mullvad on a router with Adguard)

Airvpn, or Azirevpn if you’re ok with few servers

Of those I’ve only used Azire, and it worked well. I’ve seen Airvpn recommended often though

Private internet access is nice