One of the most popular iPhone games, Galcon, has just been ported to Android.
Galcon is a real-time strategy game where you try to conquer your enemy's planets. Each planet in your control has a fleet of ships that gets larger over time. You then direct your ships to another planet to try to take it over. It is a touch-based, fast-paced quick-play game. You can have hundreds of ships at your disposal at a time, so keeping track of them all is sure to get your adrenaline pumping (if you really get into it).