Time magazine today named the Phoenix Mars Lander one of the top 10 scientific discoveries of 2008 (actually, it is #2, right behind the Large Hadron Collider, which interestingly, broke down on its maiden test and won't be operable til spring). Time said "Phoenix ...reinforced the planet's image as a once-wet place that could have teemed with organisms."
There is a nice review and analysis at Universe Today that said, "this robotic explorer captured the hearts and minds of the world; everybody seemed to be talking about the daily trials and tribulations of this highly successful mission. Perhaps it was because of the constant news updates via the University of Arizona website, or the rapid micro-blogging via Twitter; whatever the reason, Phoenix was a short-lived space celebrity." [right, credit UA]