Through Silver in Blood or Souls at Zero would definately be the best places to start for Neurosis, with Souls being the most "accessable" of their style.... but TSIB is mind-blowing.... Enemy of the Sun and Times of Grace are the "2nd stage albums" for Neurosis, that you should check out next, both are crushingly powerful.... and last is my favorite album of all time, A Sun That Never Sets, its Neurosis in a different light, this time, bleak, gloomy, depressing, and emotional, yet still quite heavy.... other albums would crush you with massive opressive walls of sound, this one crushes you emotionally.
new Neurosis album, "The Eye of Every Storm", June 29th by the way.