As they say, you can bet on anything. Here are Wired magazine's top 5 guesses about where life might be found in this solar system (yeah, other than Earth).

Their best guess is Saturn's moon Enceladus. Here is a separate Wired article about the possibility of life on Enceladus. According to this article, the smoking gun is:

Particles in a large plume of water vapor emanating from the surface suggest that the moon has an active ocean that circulates life-sustaining nutrients picked up from the rocky interior below.

Other choices include Europa, Mars, Titan and Io. (Yours Truly knows there's life on Mars or else why would there be so many short stories and novels about it?) See the first article for the reasoning behind the choices and some nice images.