Apple - Is there a GUI SSH client for OS X?

If you are looking for something that keeps track of servers/connections via a GUI, Terminal.app will already do that for you. Launch it and then from the menu select Shell > New Remote Connection. This will give you a connections manager window.

The best GUI application for SSH (and everything else you can do on the command line) is iTerm 2. While the original iTerm had a tabbed interface before Terminal did, iTerm 2 again eclipses Terminal by adding:

• Support for 256 colors (you'll never go back to 16 colors after using 256)
• Split panes (the sort of thing you can do in GNU screen or tmux, but at the level of the terminal emulator rather than in a program running on the server)
• Special provision for integrating with tmux (an alternative to GNU screen, and which most people regard as better & faster than screen)
• Terminal-level auto-completion (I don't use this feature so I can't detail how it has advantages over shell-level autocompletion: especially if you use the fish shell or zsh, then it may not be better)
• Growl support
• an Exposé-like view of your tabs
• a full-screen view (and you can choose from either its own or OS X's built-in full-screen mode; I greatly prefer iTerm's own full-screen mode, since it doesn't force you to move to a new 'Space', thus allowing Command-Tab to still work properly)
• paste history (a good complement to the shells' command histories)
• Search
• Instant Replay

and a lot more. Some are mentioned here but some are not, such as co-processes, triggers,smart selection, semantic history, and so on. Development is pretty active, but documentation seems to lag behind. I highly recommend it. I've been using it for years now and have never missed Terminal.

(It's possible Terminal does some of the things I mention here--it's been so long since I've used it that I don't recall, but when I switched I paid close attention to the differences and there were lots of advantages to iTerm. And it keeps getting better every few weeks or months.)

You could also take a look as ZOC6 seems pretty cool.

ZOC6 product page