Least successful WW2 tank?

While few people would disagree that the Elefant/Ferdinand was a unsuccessful design; too costly, too heavy, underpowered, initial lack of a self-defense weapon, shortage of spare parts, etc., I think as much blame for it's lack of combat success can be attributed to how it was used. Throwing it untested into battle at Kursk in an assault role, it was easy prey for Soviet tank-killer teams with Molotov cocktails and anti-tank mines. The German commanders should have realized that the Elefant's lack of machine gun armament, slow speed, poor maneuverablity, easy approachability from the sides or rear made it totally unsuitable as a "Schwerepunkt" weapon. This realization would have relegated the Elefant to it's intended role as a semi-static, long range anti-tank gun. And few would argue the 88/L71's usefulness as a superlative anti-tank weapon.

I agree with Shermanfreak, the Elefant/Ferdinand was a military blunder. There was a saying : What's the easiest way to put out an Elefant? Have another Elefant tow the broken down one." , or something to that effect. The Jadgtiger deserves some critisism as well. Overweight and terribly underpowered, it could only travel on paved roads and couldn't cross most of the bridges. How would all the later German designs of fared?

"It is well that war is so terrible, lest we grow too fond of it."-R.E.Lee

The Italians M13/40. Under powered, poor armament, thin skinned, even the Ausies who captured some used and tossed them when the ammo ran out.

I will agree with shermanfreak, the designers did run wild toward then end of the war. Design a super tank that can kill an entire division all by it's self.
What ever drugs they were smoking that day, please pass around.

M3 Lee/Grant:
It's main armament had very limited traverse and the secondary armament was completely inadequate for anything tougher than a truck. When the main armament could be brought to bear on armour targets there was a lot of vehicle exposed (as opposed to exposing turret only) and it was a large target.

As far as tanks that made it into battle, I'd lean towards the Elefant / Ferdinand design. Too complex, too costly, and underprotected. Big, semi mobile, steel bunker that couldn't protect itself from close in attacks.

The trend toward super heavy tanks by the U.S., Britain and Germany was rather laughable too. The U.S. T-28, the British Tortoise, and the German Maus / E-Series are a prime example of designers run amok. Just where were they going to use these big beasts and better yet .... how were they going to get them there ?