While there will be those who fixate completely on large raids by large
bombers, how about ...

Taranto. Eliminated the Italian navy's influence in the Mediterranean
theatre.

Pearl Harbor. Flawed in many ways (didn't eliminate ship repair facilities
or oil storage, nor did it catch the carriers in port AND didn't anticipate
US population's reaction), but certainly accomplished Yamamoto's goal to
allow him to "run wild" in the Pacific for 6-12 months (well, 5 months and 4
weeks actually). In terms of tactical execution (strike force performing as
the script required), absolutely brilliant.

Incendiary attacks on Japan. Switch from high altitude bombing to fire
raids quickly decimated Japan's small manufacturing base and its ability to
supply armaments factories with the subassemblies for its weapons of war.

Israeli raid on Osirak nuclear facility.

Linebacker 2. Brought North Vietnam back to the table to negotiate the
alleged end of the Vietnam war.

The difficulty in reviewing "great" strategic air missions is that what
seemed like a good idea at the time turns out to be not so good, or too
expensive or results in an unintended consequence (Pearl Harbor). While the
need for the nuclear attacks upon Hiroshima and Nagasaki seemed overwhelming
to the national command authority at the time, with the clear perspective of
hindsight they contributed little to the defeat of Japan and certainly
opened up Pandora's box for the postwar world. Similarly, the urgency to
strike the Norwegian heavy water facilities seemed an imperative, but
there's little doubt that Germany's nuclear program was not (and could not
be) supported adequately to produce a weapon in time for use.

A lot of ink is thrown at the 8th Air Force's campaign against Germany.
Certainly valor was in overwhelming supply as the crews hurled themselves at
a well-integrated defense in broad daylight with little escort (to start).
OTOH, the strategy looks remarkably similar to that British Expeditionary
force in the battle of the Somme, 1916: "Here we come, try and stop us."
Fortunately, by late 1944, they couldn't. But it was an expensive effort.

Yamamoto shootdown

Brilliant tactical execution. Strategic consequences? After all, Yamamoto
brought the Japanese the flawed Midway campaign (and overlooked some
important strategic targets at Pearl Harbor). Would his leadership have had
an impact on Philippine Sea or Leyte campaigns?

Hiroshima

See above

Paul Doumer bridge LGB

That and the Thahn Hoa raids introduced precision weapons to the tactical
air power game, but did either raid accomplish significant alterations in
the strategic picture?

Dambusters

One of my favorites.

Tirpitz

Freed RN for other duty. But considering Tirpitz never did anything in her
service life, kind of a non-event.

Norwegian heavy water

See above

Midway

In terms of fleet placement and combat orders, I'd have to agree. Tactical
execution defined "luck" for the dive bombers (Luck = when preparation meets
opportunity). When gamed by the Naval War College, the US loses Midway just
about every time.

Doolittle raid

Amen! Any time you can influence the enemy to change his game plan in your
favor, it's a good thing.