I know private internet access has proven in court that they don't keep logs, but still, trust.
https://torrentfreak.com/private-internet-access-no-logging-...
https://torrentfreak.com/vpn-providers-no-logging-claims-tes...
Of course, there's still need for some level of trust, but I think when it comes to VPNs, having public court records of the VPN provider saying they are unable to provide data in response to a subpoena is probably as good as it gets.