What's a good SSH tunneling client for OS X?
Why not just use an SSH Tunnel via OSX's built in Terminal?...

Launch an SSH tunnel

To initiate your SSH tunnel, simply open Mac OSX Terminal.app and connect to your remote server via SSH with the following flags:

ssh -D 8080 -C -N username@example.com


This will launch our SSH tunnel on port 8080 and route all traffic (securely) through the server at example.com.

Browse the Web 

Now, let’s start browsing the web using with your new SSH Tunnel (Chrome):


Open Google Chrome
Select ‘Chrome’ up the top left
Select ‘Preferences’
Select ‘Show advanced settings…’
Select ‘Change proxy settings…’
Select ‘SOCKS Proxy’
Enter ’127.0.0.1′
Enter port ’8080′
Save changes by selecting ‘OK’