My favorite German warship actually built was the Bismarck. One of the best battleships of the war.
My favorite planned German warship was the H-44. The H-44 would have had double the displacement of the Yamato battleship. It would have had 20" guns; instead of the 17" guns found on the Yamato. It was planned to have 68 AA guns; compared to 24 for the Yamato. It also would have been by far the most heavily armored battleship Germany had ever built. The intention was to make it impervious to attack.