If you want to go into Django Unchained unspoiled, then watching the second trailer isn’t the brightest idea. While the first teaser was all about attitude, this one is much more story heavy. It has the set up, the conflict, and some rather spectacular money shots. A few of those shots may be best to experience on the big screen first, so if you want to go in fresh, stick with the first trailer.
However, if you want to see more of a slave owning Leonardo DiCaprio, then check it out: