As far as 'historically informed' performance is concerned, I am always amazed at how the United States seems to have completely ignored this movement, which took root in Europe over 60 years ago. There's hardly a country in Europe that doesn't have its top ensembles playing on early instruments, and I'm always amused when discussions come up about Bach and his organ music, or discussions about the harpsichord, to see these prehistoric recordings mentioned. As if nothing had happened since...
Yes, Wanda Landowska was a pioneer, but apart from historical curiosity, her recordings are hardly relevant today. Sorry. As for Ruzickova, I was expecting a lot from this set after reading the rave reviews, but I have to admit that the sound of her harpsichord is rather unpleasant to say things politely.
As for today's harpsichordists, I recommend Céline Frisch (her recordings of Bach's two WTC books are fantastic), Jean Rondeau (all his recordings on Erato), Justin Taylor, Skip Sempé (mentioned above), Pierre Hantai (his six discs of Scarlatti sonatas are must-haves), Blandine Rannou, Christophe Rousset, Andreas Staier, Masaaki Suzuki... So many names!