Yeah. That's up there for me as well as one of the "most played". Though I do wonder if the sheer numbers of the current era mean it's eclipsed.I suppose thinking of 5e's level of success and sheer numbers, Phandelver probably ranks pretty high. But that would depend on how many of the Starter Sets sold out of 5e's big crowd, and now Phandelver and Below as well, I guess.
But I think I might still put my money on B2: Keep on the Borderlands as a contender.
It's possible Ravenloft is one of the most-read modules but I'd really hesitate to say it's the most-played. At absolute best it's second, but now far more likely a distant third behind B2 (1st) and Phandelver (2nd).Ravenloft is my guess. It has a version in at least four editions of the game.