My pick for best analogue clock program is the buici-clock. It looks good, has very few dependencies, and uses very little CPU. The second choice was swisswatch which defaults to the same Swiss Railway Clock appeareance, but is much more configurable, and also uses a lot more CPU for some reason.
The best looking analogue clock is cairo-clock but it indirectly depends on OpenGL. Yikes! It used a surprisingly large amount of CPU which I decided wasn't worth it. The OpenGL support on my graphics card is still a work in progress which may be part of the problem. Besides, too much (eye)candy will make you to sick. ^_^