Not just the image, but also knowing how that thing got down to the surface of Mars. I tried to stay up to watch the landing live (well, really, to watch the NASA and JPL guys live; there was a bit of a fourteen minute delay on the landing), but I just couldn't hang. I fell asleep at around 11:30 p.m., and when I woke up, the Curiosity rover had already made it. Heat shield, brake parachute, rocket platform, sky crane ---- all worked perfectly.
And now, there's a mountain to check out.
Happy exploring, rover. And good job, rocket scientists.