Collectability in typewriters is different for almost everyone. I like mid-century standards, some only like pre-1900 machines, some red typewriters, some toy typewriters, some less common typefaces, and still others prefer plastic 70s portables. Some treat them like Pokémon and "gotta catch them all".
Typewriters as a whole are all "collectibles"... What is your specific definition and criteria (value, rarity, popularity, etc.)?
In aggregate, knowledgeable pricing may help you determine the most collectible ranking them by most expensive. But by this ranking there aren't many of us who can buy even a single Sholes and Glidden or collect the typewriters of famous authors like Steve Soboroff.
ETC Magazine did a rarity versus desirability survey a while back of some serious collectors: https://www.antikeychop.com/mostwantedtypewriters
Interestingly, on this list you won't find many of the most collected typewriters out there as ranked by general "popularity" including machines like the Hermes 3000 or the Olympia SM3.
The Typewriter Database also has some data (albeit skewed) of the most "popular" machines ranked based on how many examples have been uploaded by collectors: https://typewriterdatabase.com/popular.0.typewriter-models
All these rankings are highly subjective though, so, again, you should figure out what's most interesting to you and create your collection from there. Figuring this out is half the fun of doing this as a hobby.
reply to u/WRSD605 at https://old.reddit.com/r/typewriters/comments/1n6nhts/remington_16/
