Finding an OS X VPN solution is not as difficult as it sounds. Most VPN services offer PPTP that can be easily used on any Mac OS. The setup is simple (here is a short tutorial: Setting up PPTP for Mac OS X) and the speed is very good.
If you are looking for a more secure connection you should choose VPN providers that offer OpenVPN. OpenVPN is a free and open-source virtual private network (VPN) application for creating point-to-point or server-to-multiclient encrypted tunnels between host computers. It is probably the most secure protocol used by VPN providers.
In order to be able to run OpenVPN on Mac OS X, you need to download Tunnelblick.
The best solution is to choose providers that offer both PPTP and OpenVPN in order to be able to try them both. Here are some good choices: