To be fair by that definition Barbarossa was the greatest strategic success of the German war; they destroyed the Russian army in place and then destroyed half of Russia's fighting ability. That the other half was still a relevant threat isn't the same as a strategic failure.
I am going by memory here and typing on a phone from a balcony in Costa Rica ... According to Fisher (who extensively examined the remaining Wehrmacht archives), the German Wehrmacht strategy for 1941 was 2x500km advances (as in sequential advances across the whole front not individual army group) that would see the principal destruction of Soviet forces in the Western Soviet Union. To my knowledge, both of goals were accomplished. What Germany failed to do was to turn these into victory. However, I think that our concepts or definitions of 'strategy' are different. Continued below.
Or, in other words, I disagree with your definition of strategic; the combination of El Alamein, Torch, and Husky was strategic (freeing up the logistics chain through the Mediterranean and incidentally also knocking out Italy), but none of those three operational successes was a strategic success by itself. The German invasion of Western Europe in 1940 was a strategic success (knocking out the western front, i.e. France and support) with a two-stage operational success underpinning it (Fall Rot and Fall Gelb), but neither of them alone would have been - you could pin all the strategic success on the last part (i.e. Husky and Rot) but that seems unfair.
I think what you are talking about are grand geopolitical aims ... From my perspective, strategy are the actions you take to achieve those aims. And, the leaders of the time agree with me ... At the Arcadia conference (the first strategic planning between UK and USA), British Chiefs of Staff communicated their strategy to the USA as that of: maintaining the naval blockade and stepping up the strategic bombardment to economically cripple Germany; to sustain the Russian front by arming and supporting them; and to regain full control of the North African coast to fence in the Axis; all with the aim of limited land invasion of Europe in 1943. See allied strategy in world war II by Dr. Lemar Jensen (who directly cites the Arcadia minutes).
In response to both yourself and
@Graf Zeppelin , all of these strategic objectives were met. The battles that followed Alamein allowed Britain to reinforce it's position in the middle East, recapture the North African coast line (withTorch/husky completing the job) and support closing the ring around Germany. Again, the aim was to defeat Germany, the strategy is how you achieve this. Even the planners at the time considered the 'how you achieve your aims' to be what constitutes strategy. Alamein Was decisive battle, through which operational planning ensured the tactical success supported the strategic aims. The whole concept of the 'set piece' here was that it was really a 'decisive battle' supported by operational planning.
How did Alamein relate to strategic success ... Closing the Mediterranean allowed the axis powers to be isolated, and allowed the allies to better concentrate their available forces (particularly the landing craft necessary for Neptune). It economically isolated the axis and provided the opportunity to knock one of the axis powers out of the war (further isolating Germany and forcing her to further dilute her own strength).
As for Britain having no strategic balance to the defeat of Germany/Japan. After Dec 1941, the geo-imperial-political aims changed from how do we defeat Germany to how does Britain maintain global standing in the post war era. Thus, things like the reconquest of Burma and Malaya are strategic successes from that context.