There is no definitive answer to who the best performer of Mozart's Piano Concerto No. 21, 2nd movement is, as it is subjective and depends on personal taste. However, some notable performances include those by Géza Anda, Mitsuko Uchida, Vladimir Ashkenazy, and Daniel Barenboim[3][5][6]. Each of these pianists brings their unique interpretation to the piece, making it a favorite among classical music enthusiasts.
Sources
[1] Mozart - Piano concerto no 21 - 2nd movement - YouTube https://www.youtube.com/watch?v=FZNt3ESnf8Q
[2] The 20 best piano concertos of all time - Classic FM https://www.classicfm.com/discover-music/instruments/piano/best-concertos-all-time/
[3] Piano Concerto No. 21 (Mozart) - Wikipedia https://en.wikipedia.org/wiki/Piano_Concerto_No._21_%28Mozart%29
[4] [Discussion] Mozart's Piano Concerto No. 21 in C Major, K.467 https://www.reddit.com/r/Mozart/comments/uxhiw6/discussion_mozarts_piano_concerto_no_21_in_c/
[5] Mozart's Piano Concerto Number 21 https://myfavoriteclassical.com/mozarts-piano-concerto-number-21/
[6] Remixing Mozart's Piano Concerto No. 21 – Andante https://www.ethanhein.com/wp/2020/remixing-mozarts-piano-concerto-no-21-andante/
[7] Mozart - KV 467 - Piano Concerto No. 21 | Classical Music Forum https://www.talkclassical.com/threads/mozart-kv-467-piano-concerto-no-21.85337/
[8] Pollini plays Mozart Piano Concerto No. 21 2nd mov ... - YouTube https://www.youtube.com/watch?v=8XAYOy66GRw