Regarding easy setup and more stable access that works well on PC, Mac, and smartphones, what are the best virtual private networks (VPNs) for use in China?

Well, to be honest, If you need some professional vpn service, I believe you can definitely buy vpn service. It would be the best choice. They have wonderful features coupled with very cheap vpn packages and webmail access are amazingly rich and intuitive interfaces. Simply give them a try