Primus over at Brickcommander has some incredible tank designs in MLCad from the Mechwarrior series. I suggest you head over there and look at his Mechwarrior vehicles section. The Behemoth II and M1 Marksman are ace builds.
Keldoclock wrote:STDs are tanks that would be absolutely absurd IRL.
AT LEAST 1.5 times the size of this:
^that rope is waist high.
MAUS VII Superheavy Tank, a prototype Piltogg project began in 1943. The main gun is 128mm, and the coaxial is 75mm, or the size of a medium tank of the era's gun. An STD, then, would have about a size 12 cannon.