Is this a continuation of the series? Who knows...
What do you think was the most effective German tank destroyer of WWII?
Also, a side question: Should the StuG be considered a tank destroyer or not? Although it was designed as assault artillery, it was very rarely used for this role. Many commanders and units considered them to be panzerjagers, others simply used them as tanks. There was conflict between commanders as to whether the StuG was a TD or not. They also claim to have destroyed the most allied armored vehicles during the war. What do you think?
In my opinion, the StuG was an infantry support vehicle rather than a tank destroyer. The most powerful tank destroyer was the Jagdtiger, but the best was the Jagdpanzer 38(t). A lighter design was easier to produce and was easier to conceal. These qualities are some of the most important for a tank destroyer.
"What do you think was the most effective German tank destroyer of WWII?"
Depends on how you define efficiency. The StuG knocked out the most tanks of any WW2 AFV, which can mostly be attributed to the great numbers of StuGs used.
However, I'd say that the most effective German TD was probably the Marder series, because they were obsolete vehicles that were refurbished quite effectively as TDs. From a "bang for your buck" standpoint, the Marder was the best, because their cost/benefit ratio was very favorable.
"Should the StuG be considered a tank destroyer or not?"
Tank destroyer was a doctrinal concept. Later models of Stugs with the long 75mm were frequently used as tank destroyers, so that's what they were - when fulfilling that role.
Although it was originally not designed as such, if you look at the Jagdpanzer IV - A purpose built TD - There's not much of a difference between that and the later StuGs.
Compare that to the MG42, which was used as both a LMG and HMG.
So - Yes, the StuG was a TD, when it was used as a TD.