I’ve had over the years Harber, Von Holzhausen, incase, Hard Graft and now Ryan sleeves for my MacBooks.
I like the VH envelope for my last machine but they’re very expensive and a bit heavy for my new MBP16.I also liked the old incase icon sleeve but they don’t make them for the 16. I’ve gone with a Ryan leather sleeve and it’s really nice - good leather, very well stitched, monogrammed and in a lovely colour (turquoise and orange). And it was a good price relative to eg Woolnut, which was also a good sleeve.
(I wouldn’t go with the Harber or Hard Graft sleeves again because both of them stretched too much, too quickly and became baggy).