The first thing you have to get away from is the idea that any tank could be best at anything during the hole of the war. If a tank is best at one thing, it usually is not best for long. Progress in tanks was pretty fast on all sides.

The second most important thing is that you don't just look at specs but understand the tank doctrine, and that as a extention of overall doctrine. So the best tank, is that tank that best fits its intented roll as part of a larger doctrine. If your doctrine fails, even with better tanks you are not going to succeed. This is were I would focus the majority of study, instead of looking at specs.

Every nation devloped different classes of tanks for different roles. There are many tradeoffs to be made.

Some tanks that were pretty good:

• France had the Char B1 and SOMUA S35 and they were ahead of what the germans could offer at that point. However they were never employed very well. I mention them largly because the often get ignored, because people think that france could not have had good tanks, if they lost.

• Panzer III and Panzer IV while not exeptional on paper, it was optimal for the role it was intented to play. The Panzer IV remained the main tank for the germans for the rest of the war (of course it was upgraded during that time).

• The Soviet T-34 was the main tank used by the ruissans and it proved effective. When it first rolled onto the battlefield it was the best tank in the world and caused many problems for the germans. It was optimised for easy production and is the second most produced tank of WW2.

• Sherman M4 was a very impressiv tank, and it served threw out the rest of the war. It was used be many of the allies. The tank was well made for american tactical doctrine. Most produced tank in WW2.

• The British Centurion tank never made it into battle but it was a tank designed during WW2. It was the first of a new generation of tank and with some upgrade serves to this day.