One of the shows I watched, that I really liked, was the series V. It begins with a race of extraterrestrials coming to Earth. They show themselves to the world and appear to look human. Little by little the "visitors" begin showing the abilities of their technology, trying to convince mankind that they are here to help.
Although many humans see the "visitors" as saviors, some see them as a threat. The V's leader, Anna, begins manipulating humans to get them on her side. Later it is discovered that many of the V's have been living on Earth for many years. Slowly embedding themselves into roles of power, waiting for the mother ship to return.
Morena Baccarin is great as Anna and Elizabeth Mitchell is a very good lead character. I wish the would have continued this show a little longer. It had lots of potential. Let me know if you watched the show and what you thought.