Played the op. 26, and despite a few tricky parts, it's actually way easier than it sounds (by no means am I calling it easy). As for my favorite, I don't think I really have one. It's not a form I pay much attention to but if I had to pick a few it'd be Chopin's op. 22, 44, 61, and the one from Scriabin. The "a la polacca" section from his op. 2 (chop) is also a personal favorite. It may not count as its own piece but it is a pretty fun polonaise like variation.