I've been using ExpressVPN for a couple of years now and so far I haven't had any issues with them whatsoever. My subscription ends in 2 weeks and I see here that some people raised legit concerns regarding them and privacy they provide so now I am looking at the competition and seriously thinking about getting something else.
I think that Mullvad is the best VPN you can buy anonymously with cryptocurrencies, but they are certainly not the cheapest available option.
If you have Coingecko account with collected candies you can use their code and get a nice discount for Surfshark VPN with 24 Months + Free 3 Months, or 18% off on NordVPN.
You can also try Windscribe or Proton free versions but for anything serious you will need to pay pro version.