Paid-for VPNs are generally thought to have better privacy, security and functionality than the free ones, but they still might not be perfect in those respects.
If you're particularly loathe to pay, I've read that ProtonVPN, Windscribe and TunnelBear are worth considering, but I've never used them. It's hard for me to recommend any VPN as being suitable for any particular individual because a lot depends on the person, and the criteria for choosing one are complex. Depends what you want to use it for.
I've used VPNgate and didn't notice any security or privacy problems, but how would I know if it was leaking? Functionality didn't seem that great - it was usually OK for browsing but some websites knew it was a VPN and they wouldn't play ball. And I don't think I got very far with downloading large files. And the region(s) I wanted to "be in" weren't always available to pick. The service depended on volunteers in various countries allowing me to use their computers as proxy servers, and sometimes they just didn't show up in the list.
All in all, I'd say act on any recommendation with caution, and research the criteria that matter most to you before paying out or running the program, though I'm not saying recommendations are necessarily wrong.
Tip: Microsoft locked me out of my email account when I ran a VPN without first closing my email client. It seems they were suspicious that I'd appeared to cross the Atlantic so quickly, and so they thought I'd been hacked. But then, some service providers can get nasty like that even if you just travel to another country. And I got them to let me back in again eventually. They might not have been such butts about it if I'd had 2-factor authentication. Facebook logged me out but didn't make it hard for me to log in again.