Good ol’ Matt is right on the money with this post.
Not only is a one-way manned trip to Mars viable, I think the concept is much much cooler than a wooncy two-way trip. My pick for first one-way mission: China. They have a strong precedent for self-sacrifice, and an overwhelming desire to prove themselves to the rest of the world.
Bring on gene-therapy so I can make myself into a Chinaman!