This is an easy-to-set-up VPN to use, with a well-known privacy-oriented company, and it's fast, i.e. the speed drop is not at all noticeable even with the free (non-media) bandwidth.

Unfortunately, if the extension is kept running while the computer goes to sleep, etc., the internet connection for the browser becomes unstable, including not being able to connect to any website. Turning off the extension restores the normal connection, but turning the extension back on still causes problems. At this point, removing and reinstalling the extension is required to get it working again. This is non-ideal. Some other reputable VPN providers may be easier to work with than this.