Got a little confused. Location of VPN company or the location you connect to? If its the location you connect, then USA. If its location of main Office, then prefer the country which respects privacy and doesn't fall within 5 eyes, 14 eyes or whatever eyes.
I'm mainly using Windscribe connected to Switzerland = great privacy and still decent speed.
Currently testing ProtonVPN... speeds are like twice as good then Windscribe lol
I don't use one much but when i do i use Windscribe and there are lots of locations not included in my version so tend to pick the one with the strongest looking signal or use a US one.
The United States so that I can get some of the US Netflix "exclusives" not available in Australia
Other times I choose the one with the fastest response time
Well, There are many servers in VPN but mostly use USA location due to many of services are restricted out of USA. USA location in VPN is most favorite but there is an issue, most of the peoples are connecting with USA server location, that why I face lack speed.