I am very interested in VPN tech,not that I am an expert or anything,but i would like to hear from this forums members what you feel comfortable using and what knowlegde you have picked up in the past or present.
My favourites is Ekspressvpn, Vyprvpn, surfeasyvpn and Windscribevpn
It depends upon what you want to use a VPN for. If it is for online financial transactions then any reputable VPN service will suffice. For privacy and anonymity that is an entirely different matter. You also have to consider server locations, the number of servers available, reliability, speed, server security, the installed client, features you might need like obsproxy, cost, mobile device options, etc.
I am currently using IVPN on Windows PC. It's reliable, speed is good, and meets my basic online encryption needs. I don't use it for privacy\anonymity. It's a relatively expensive service though at $100 per year.
For basic protections against MitM attacks at public wifi, FrootVPN is a cost-effective choice. For an occasional online bank login SecurityKISS free would suffice. If you don't want to go the free route, then JonDoNym using their annual 1.5 GB plan for $14 is a very good option for login to bank account and take a quick look, perhaps download a bank statement, and then logout. 1.5 GB should cover the entire year for that purpose.
If you're hardcore about anonymity and privacy then a VPN alone isn't sufficient. It's a vast topic and requires extensive research of the multitude of options.