What FICS chess clients are available?
Solution 1:
A bit late, but you may want to try Raptor (from code.google.com or github.com*)
You won't have a ppa but they provide .deb installers for 32 and 64 bit Ubuntu systems. Has a very nice and customizable interface and is regularly updated (has its own autoupdater which you can turn off if you want, of course) Another option would be Eboard. Last but not least, you can try Jin but you will need to install Oracle Java to solve an annoying sound problem with openjdk.
* The project has been moved to GitHub after the Google Code shutdown announcements.
Solution 2:
It is possible to play chess on FICS using SCID. It can be installed in the usual way:
sudo apt-get install scid
Solution 3:
I think the best software for FICS/ICC is eboard (in the repositories).
Solution 4:
I like PyChess the best of all the alternatives that I've tried (and I think I've tried them all by now!)
To install: sudo apt-get install pychess
I have had problems with previous versions, but there has been a lot of work done on it lately and I no longer have any problems with it