Breach is a suspenseful thriller. It is interesting that you know who the bad guy and good guys are from the beginning, yet you still are kept interested by the story arc and acting.
This is not a movie that you need to go to the theater to see. There is almost no action, and no special effects. It's an old-style thriller, plot and mood driven, rather than action driven.
I liked the movie, but it's never going to be one of my favorites. Excellent acting, and credible storytelling. I'll give it a "single shot" on our scale (Why bother > Drip > Shot in the Dark > Single shot > Double shot).