Hitler definitely considered Bismarck one of the greats that Germany produced.

Hitler thought one of the greatest faults of Germany was that it united so late. The French and English unified much earlier, because of this, they were able to grab more oversea territories and influence history significantly. Bismarck was the man to finally unite the German states into a single entity.

Hitler also commented once that one of the Kaiser's biggest mistakes was getting rid of Bismarck, the man who kept peace, yet strengthened Germany (similar to something Hitler attempted to do in the late 30s). (Side note: Hitler thought the Kaiser's biggest mistake was alienating the British in the build up to the war, without this, Hitler thought the British would have stayed neutral.)

Another instance we see Hitler's admiration of Bismarck is when dealing with his own foreign minister, v Ribbentrop. When the Nazis were in their peak of deception, getting all of Czechoslovakia, Hitler gave some credit to v Ribbentrop. When sitting around the a fire with the Nazi big wigs, Hitler affectionately called v Ribbentrop "the new Bismarck" or "My Bismarck". I've seen the conversation quoted both ways.

Hitler, Adolf, and H. R. Trevor-Roper. Hitler's Secret Conversations, 1941-1944. New York: Octagon, 1972. Print.

Shirer, William L. The Rise and Fall of the Third Reich; a History of Nazi Germany. New York: Simon and Schuster, 1960. Print.

Stargardt, Nicholas. The German War: A Nation Under Arms, 1939-1945: Citizens and Soldiers. N.p.: n.p., n.d. Print.

edit: Grammar