I'd say that the two helicopters that entered service while he was still making test flights in the VS-300 (which never entered production) jointly held the title of "first practical helicopter"!
Admittedly, the mass-produced Sikorsky R-4 was just a couple of months behind these examples.
Fletner Fl282 (the world's first series production helicopter): operational 1943 from shipboard in the Aegean, Baltic, and Mediterranean, often in extreme weather conditions, as single-seat observation and small-cargo helo and from land as a 2-seat liaison (artillery-spotting) and recon helo.
Focke-Achgelis Fa223: entered series production in mid-1942, used in 1944 to recover two crashed aircraft in high-altitude terrain, and was used to transport troops and sling-loaded artillery guns at altitudes up to 5,200 feet (useful load 1,500 lbs, max payload 2,200 lbs).
Service ceiling: 6,600ft (vertical climb), 16.000ft (with some forward movement).
2 crew. 4 passengers in cabin with 8 more on seats attached to the outriggers.
Large-scale production of these were thwarted by Allied bombing raids, however.
I'm fortunate to know Sergei Sikorsky well. Elena and I have waged a notably unsuccessful two-front campaign trying to get him to write his memoirs but at 97 he's not much motivated. Which is a genuine loss to aviation and wider history. One of THE best examples of contributions by legal immigrants. Besides that, Sergei is a gifted story teller. Among other things, he realized that Girls Are Different when Howard Hughes landed at the factory after his world flight. He introduced Ginger Rogers, who wore a skin-tight clingy white dress...