I love the thought that has gone into Deepclocks analog desktop clock. You can have it disappear when the cursor goes over it so that it is not obscuring what is underneath it. It stops disappearing when you press the option key so you can move it. They have 15 clock faces to chose from. Obviously I like seeing an analog map of what time it is, rather than digits. DeepClock does a lot of other things, like calendars, but I use it for the clock and I recommend It highly.