Eh... quite simply it's the record of opposing men, materiel, transportation and buildings destroyed by stukas from '39 to '45. Rudels final tally alone amounted to over 500 tanks, at least 1000 other vehicles, 150 artillery pieces, at least 11 planes, a couple of trains, assorted boats, one battleship, two cruisers and a destroyer, oh and a couple of bridges, allied positions, airfields, roads, rail lines etc. Just one guy in a stuka. His unit's tally on the eastern front was enormous and it wasn't the only unit. It was by far and away the biggest flying tank killer in military history. Their operational successes weren't just restricted to the Russian theatre either. In the early stages of the war in every German operation, from Poland to the Fall of France the Stuka inflicted enormous losses on the opposing forces. Hell the very first air to air "kill" of the war was made by a stuka over Poland. It formed one of the main backbones of the very successful Blitzkrieg tactic.
The others you name have among their number some fine aircraft, the Mossie being an outstanding aircraft, but equally some right duds that had little effect operationally. The Beaufighter was outclassed across the board from it's maiden flight, with only later development as a nightfighter and the skill of it's crews making it anyway useful and is so far away from the Ju87 in effectiveness it would require the services of the Hubble telescope to spot it. The Shturmovik was underpowered, overweight and couldn't hit a barn door from ten feet. Most of it's successes were down to sheer numbers thrown at a target. Neither compare to the operational successes of the Ju87.
BTW the stuka could carry a higher bombload (4000lb)than the Dauntless, the ilyushin, the Typhoon, P47, Tempest, Beaufighter and equalled the later F4U variants and the P-38.