There is a lot of shitty software out there but there are some exceptions. In my experience, the following is not half bad. As a rule, all software on the following list is Free Software.
Wireguard is an extremely well-engineered VPN software and protocol. It is built around the insight that simplicity is a key requirement to minimize attack surface. This garden used to use Wireguard in its plumbing to attach to the Internet but can do without these days.