Wizard Nightmare Build submitted by TornEternity.
This is the build I am currently using to solo Act I of Nightmare. It may not be optimal, but compared to each of the other builds I have tried here, this one seems to have the most survivability with a nice damage output.
I am not going to explain each skill as it should be pretty self-explanatory.
I try to keep my Vitality and Intelligence about equal to sustain life, but continue damage output.