Complex sentence: In addition to winning its third consecutive award for Outstanding Drama Series, "The West Wing" achieved a milestone on the night when it became the third show (all dramas) to gain nine acting nominations for its main cast members.
Split into simpler sentences: In addition to winning its third straight Outstanding Drama Series, "The West Wing" achieved a milestone on the night. It became the third show (all dramas) to gain nine acting nominations for main cast members.