Favorite set of Variations???

Hello everyone!  Thought I'd share my favorite set of variations that got me into composing variations after I played it on piano.  What's your favorite?  (the piece is only 10 minutes long but the YouTube video is half an hour because it includes three different performances of the piece):

The Beethoven variations in C minor are definitely up there (as well as his Diabelli variations).

My absolute favorite set of variations though is by a lesser known (and in my opinion, incredibly underrated) French pianist-composer, Charles-Valentin Alkan, his "etude" Le Festin D'Esope where each variation is supposed to represent animal from Aesop's fables.

Here's a version with the sheet music.

Though, this is the best overall performance of these variations in my opinion:

The 32 Variations in C minor is up there, definitely. I've heard that it's like a Baroque Chaconne(Variations on the melody over a repeated, usually short bass). But my favorites would have to include the 18 variations on the Ode to Joy theme of Beethoven's Ninth that I so carefully timestamped in the comments of this video and got a lot of thanks for:

In fact, most of the Theme and Variations I have heard have been in the form of either symphony movements(Beethoven 3 and 9(both in the Finale after an intense start)), concerto movements(Mozart PC 24(Andante movement) and HC 2(the Rondo of HC 2 essentially is a Theme and Variations in disguise)), or Chaconnes of Bach and Pachelbel, and not an isolated Theme and Variations labeled such(although a few I listened to are like that including 32 Variations in C minor by Beethoven and 12 Variations on Twinkle Twinkle Little Star by Mozart).

There's a few variation sets I've been enjoying as of late (mostly Slavic in origin), here are some of them:

Vasyl Barvinsky - Variations for piano sextet: 

Vissarion Shebalin - Piano Trio, mvt. 3: 

Anton Arensky - Variations On a Theme by Tchaikovsky (from String Quartet no. 2, mvt. 2): 

Boris Lyatoshynsky - Piano Trio no. 2, mvt. 4: 

I also like the Beethoven C minor variations, they are probably the most quintessential of all variations. But these are just some I think are also really great, and really creative.

I thought I'd mention this set of variations of "Twinkle, Twinkle Little Star" by Ernst von Dohnanyi:

(I set the video to start after the boring and overblown introduction which is meant to give a melodramatic and ultimately comic effect when the theme comes in on the piano)

@PeterthePapercomPoser The Passacaglia variation is probably one of the most awesome pieces from that time.

I've personally always really enjoyed Salieri's "26 Variations on La folia di Spagna"

Tough one, and I agree with some such as Beethoven's C minor variations and Alkan's Festin.

Some other sets I love are the slow movement of Scriabin's piano concerto, and Szymanowski's two sets of piano variations.

Probably the 2nd movement of Beethoven's Op.127. If not that then the 3rd movement of the Op.135, the 2nd from the Op.111 or the finale from the 3rd symphony. And if you consider the Art of Fugue some kind of meta set variations that one of course. Also still waiting to the day I can properly understand the 4th movement of Beethoven's Op.131.