The Top 10 World War 2 Tanks(IMO.)

10. The T-34(U.S.S.R). The T-34 tank was used massively in World War 2, It was a Soviet Medium tank, And was introduced in 1941 before the Germans committed Operation: Barbarossa(Invasion of the U.S.S.R.)

9.The Carro Amato L6(Italy). The Carro was used by the Italians, Although outclassed, It was continued to be used in North Africa, The Balkans, The Eastern Front, And Italy unil the end of World War 2. 

8.The Churchill(Britian). The Churchill was used as a Infantry support tank by the British. Used in almost all theatres of war the British fought in, It wasn't very reliable however and often broke down.

7.The JS-4(U.S.S.R).  The JS-4(Josef Stalin 4) tank was used as a spearhead for the Soviet tank forces on the Eastern front, After the battle of Kursk a larger gun then the 85 mm was needed. The Soviets came up with this.

6.The Sherman/Medium Tank M4(Britian, U.S, U.S.S.R(To a extent).  One of the most widely produced tanks in World War 2, The M4 was used by both the British and the Americans, And to a extent, the Soviets.

5.Pz. Kpfw. Maus(Germany). The Maus, although never seeing combat, Its armor would've have made it almost invinsible to any anti tank or tank gun of its day. But it would've been almost impossible to move due to its poor mobility. It would have been used by the Germans.

4.Char B1(France). The Char B1, A French Tank(Never thought the French would make it on this list, Would you?) After WW1, The French wished to modernize its tank forces.

3.Tiger Tank(Germany). The Tiger Tank was used by German forces in World War 2 and is considered one of the greatest tanks in it. It first saw action in 1942 and was the first mass produced heavy tank the Germans did.

2.Pz. Kpfw. I(Germany).  The first mass produced tank the Germans did after WW1, This tank played a important part in the German victories of Poland and France.

1.Pz Kpfw Panther(Germany). The Panther was the first true main battle tank of the German army in WW2, The combination of its armor(Sloped), Its powerful gun and great mobility made it the best, In my opinion, Tank of World War 2.

HONORARY MENTION:

The Type 95 Ha-Go Tank(Japan).  These tanks were the most numeriously produced tanks the Japanese made in WW2, It was used throughout the war.