Months ago, I started with Tunnelblick. But with Mac OS X 10.8.x, I had to move to the beta 3.x versions. And it was rough, I couldn't connect, the new version didn't convert the old version's data, etc.
When it was good, it was really good. But since Tunnelblick is still in beta - for several months now, I had to move on. So I paid for and now use Viscosity - which works really well and has regular updates which are not beta. I doubt I would need to move back to Tunnelblick.