A very well-made television series on the Sci-Fi Channel, currently in its second season.

The premise: A lost book of Nostradamus predicts the destruction of earth by an alien force in three waves. During the First Wave, aliens plant spies among us, to infiltrate our society, perform experiments on us, and gain positions of power within our governments. In the second wave, large alien armies are transported to Earth and assert total control over the planet. The third wave is an all-out destruction of humanity.

We are now in the first wave. This has been the case for most of the century by my guess, though no exact numbers are given.

The two main characters are Cade Foster, an escaped alien test subject who was subsequently framed for the murder of his wife, and Eddie Nambulous, a paranoid computer genius. They found the lost book of Nostradamus, which gives them cryptic clues as to how to find out and destroy the various alien installations and experiments. Together they fight the entire alien presence on Earth, but somehow the aliens are still expanding rapidly.

My advice: If you get the Sci-Fi Channel, you should definitely give this one a try.

Update (10-29-00): Sadly, First Wave has been cancelled. I personally think there were plenty of aspects left to explore for at least 3 more seasons, but the TV execs didn't seem to agree.