According to Wikipedia:
The first fully controllable helicopter (as opposed to autogyro) was the Focke-Wulf Fw 61, demonstrated by Hanna Reitsch in 1936 in Berlin, Germany. ( http://en.wikipedia.org/wiki/Focke-Wulf_Fw_61 ) so it is likely that there were German military helicopters during WWII - especially given Hitler's love of 'wonder weapons'.
On the tank front, my old man had some good words for several of the English tanks (Churchill - "slow but tough", Cromwell - with the govenors removed = "so fast nobody could hit it") but was in absolute awe of the later German ones. Having said that, he was always a fan of "light but fast" as being (in his opinion) safer than heavily armoured and slow, but then he would be since his favourite vehicle of the war was the Daimler Scout Car. If I remember rightly, the Scout Car had a preselector box and an additional rearward facing steering wheel (for use by the commander) and when 'bumped' (fired upon) could be reversing at speed within seconds - a feature that saved his life on several occasions - and hence is the cause of me being here to bore you with this
Rog