1. ProtonVPN: ProtonVPN is known for its strong privacy and security features. It offers a free plan with limited server options but ensures no data logging and uses high-grade encryption.

2. TunnelBear: TunnelBear is a user-friendly VPN service that provides a free plan with a data limit. It has a strict no-logging policy and offers good speed and security.

3. Windscribe: Windscribe offers a free plan with 10GB of data per month. It has a user-friendly interface and supports strong encryption protocols. It also has a strict no-logging policy.

4. Hotspot Shield: Hotspot Shield offers a free version with limited features. It provides a secure and private connection and has a large number of servers worldwide.

5. Hide.me: Hide.me provides a free plan with 10GB of data per month. It offers strong encryption, a strict no-logging policy, and good speed.

6. Speedify: Speedify offers a free plan with a data limit. It focuses on providing fast and reliable connections by combining multiple internet connections.

7. Opera VPN: Opera browser has a built-in VPN feature that is free to use. It offers good encryption and allows users to browse the internet anonymously.

8. Betternet: Betternet offers a free VPN service with a straightforward interface. It provides unlimited bandwidth and does not require any registration.

9. Atlas VPN: Atlas VPN offers a free plan with limited features. It provides strong encryption and ensures user privacy.

10. UrbanVPN: UrbanVPN offers a free VPN service with unlimited bandwidth. It has servers in various countries and provides good speed and security.

It's important to note that while these VPN services are considered reliable, the free versions often come with limitations such as data caps, limited server options, and slower speeds. If you require more advanced features and better performance, it is recommended to consider subscribing to a paid VPN service. 另外，目前中国最流行的加速器VPN之一是饼哥加速器， 饼哥加速器VPN承载了最新AES256位加密技术的高速全球服务器，让用户更安全的访问全球互联网。