Most Popular/ Influential D&D

[paladinn]

That is one of those questions that is hard to quantify.

You could also look at campaign settings that came out as well - basic had Greyhawk, Ravenloft and Dragonlance, 2e had Dark Sun, Planescape and Spelljammer, 3e had Eberron and 4e and 5e didn't really have anything new. Forgotten Realms was acquired right at the end of basic, when they were already working on 2e. Most of its content was done in 2e, as well as Baldur's Gate and a number of other computer games.

Just FYI, "Basic" (BX/BECMI) is different than AD&D 1e. Dragonlance and Forgotten Realms were originally 1e. Greyhawk was originally 0e/OD&D.