As long as your horizon extends farther than manned missions, it's a pretty good time to be a fan of the space sciences. There are a number of terrific space probes out and about in the solar system (and even slightly beyond). It's truly incredible to go outside on a dark night and imagine that we've got little robots whizzing around visiting some of the neighbors.
My favorite active spacecraft are:
Opportunity and Spirit
Until NASA calls it for Spirit, I'm sticking with her. In the cosmic scheme of bang for the buck, these two little girls have definitely reset the bar. I have friends who joke that I can't go to the restroom without having an adventure, but Opportunity is the queen of the pop-up adventure. She's found so many meteoroids just lying on the surface of Mars that it seems as though someone held a galactic rock concert and she's the clean-up crew.
Dawn
Dawn is going to orbit the asteroid Vesta and then she'll wander off and orbit Ceres. How cool is that? It's moderately neato to actually visit an asteroid, but hopping between the (dwarf) planets is what the future was supposed to be about. Of course, doing it with an electric engine is so 21st Century, too.
Voyagers 1 and 2
The ultimate Energizer bunnies. The first man-made objects to leave the solar system. They're out there in the great beyond now. One neat thing about the Voyager Interstellar Mission is that they are calling home with 23-Watt radios. This is less power than a standard marine-band VHF radio.
