The nature of the usage usually dictates the solution.
If it’s work related, I would hope your employer has something in place, I mean what sys admin is going to be comfortable with you connecting in from a random VPN provider because you bagged a cheap ‘deal’ on Groupon?
Generally it’s simple, if you want stupidly cheap/free, can live with some highly dubious hiring choices and the odd bit of whitewashing incidents, but value a track record of generally doing what they claim, PIA/Nord are OK choices with the appropriate Quidco/TCB offer. If you absomotherlovinglutely need privacy because your risking arrest/imprisonment/torture/your life and you’re not into that kind of thing without a safe word and lube, it’s probably worth going for something with a slightly higher standard of security/privacy. Also remember that in some countries, laws are selectively enforced depending on what passport you carry and who’s trying to lean on who.