On the 10" size, I think few can beat the design of an IBM 701 [1] with its butterfly keyboard. I would be cool if this were to make a comeback: a 10" screen couple with a 12" keyboard. The Sony Vaio P laptops were also cool with their 8" wide screens, but their keyboards were somewhat cramped. [2].

At the 8" size category, a Pixel 9 Pro Fold coupled with a decent foldable keyboard, perhaps something like [3], is a killer combination. My personal favorite keyboard in the foldable category was the TextBlade [4], which, sadly, never materialized.