Sorry for the late reply.

Per @rambos@lemm.ee it depends at least to some degree on your needs. Mullvad is a popular and well-respected option (though it is the very provider rambos is alluding to because they recently removed the port forwarding feature because there was no way to implement it without negatively impacting privacy - a positive thing for privacy, but a negative thing for those who need the feature). I'm also a fan of IVPN because they open source all of their very high-quality clients (as do Mullvad) and they cater to a more technical audience. Proton has been getting some decent press recently for open sourcing their clients, but there's a rumor going around that they're actually reselling NordVPN which is one of the less reputable providers.

Happy to provide more points of interest with more context on your needs.

Short answer by making a few assumptions: Don't patronize PIA unless you can't or don't want to pay for better, and the built in torrent client is fine if you're happy with it, but qBittorrent would be a good match with your desktop environment if you want to try something else.

Happy to answer questions in like 10h when i'm awake again lol