Cassini is doing some awesome work. I've been watching the website ever since orbital insertion in 2004, and it keeps returning gorgeous images of the moons and really interesting science. Apparently it still has lots of propellant left, since it's been approved to continue to about 2017. The web site doesn't have a photo gallery of the best pictures, but the daily pictures, which have some interesting write-ups are archived at http://saturn.jpl.nasa.gov/photos/.