I really like this one, a A. millepora. The body is sort of a rust color, but the polyps are a light lime green. The picture doesn't really do it justice.
Thanks guys! This is another one I got a few weeks ago. It was thrown in for free! It's a tiny yellow seriatopora. The frag is only about .5" high, but it's started to grow now, and the tips are turning pink, so I'm hoping this will grow up into a cool coral.