On another thread, it was opined that the Underwood Model 5 (not to be confused with the Underwood Touch-Master 5) is the crown jewel among typewriter collectors because it's open, the old black paint and gold decals gives it a certain charm, and it gives the look of the true author's typewriter.  Therefore, you find a lot of these going for as much as $250 or more, and a lot of these are most certainly not in working condition, let alone good working condition.  Then, among a lot of our members, the Olympias are very popular because they are a finely-tuned, high-performance typer that could only be brought to us by that good ol' German over-engineering.  I know and definitely appreciate both machines, as I have owned many versions of each.  But, I've got to tell you--Underwood Model 5 machines are definitely primitive and very clunky compared to the velvety smoothness of an Olympia SG-series machine.
 
But who is to say which typewriters are the collectible ones?  Which ones are the most hotly sought after?  Which typewriters, besides the Olympia (which is a VERY good machine--the Mercedes Benz of typewriterdom), have the collectibility factor?

I think a case could be made for the following:

The "Easter-Egg" Royal QDLs--good typewriters, though not as solid in feel compared to an Olympia SM-series, but a fairly rugged and reliable machine nonetheless.  The remark was once made that their escapement mechanisms weren't up to par, but upon my examinations with scores of these machines, I have found no trouble or signs of any major wear.

The legendary Royal HH--very good typers--solid, rugged, reliable, will outlast you and your grandkids.  These machines are tanks, but most of them are colored in that drab brown with green keys.  Not too bad if you like earthtones, but it can get monotnous.  Some of the later ones were painted in the "Easter-Egg" style, but I have only seen one silver-colored one.  Some people have even said that although they are a solid machine, they lack features such as an extended back paper rest, and half-vertical-spacing.  It is typical among American-made typewriters--especially the early ones. 

Underwoods made between mid-1946 to 1963--These include the Basket-Shifting Underwood Rhythm Shift all the way to the Touch-Master Fives.  I have never been able to figure out why it is that whenever I get one from this group, it almost always needs at least three or more adjustments (especially the shift alignment), a good cleaning and a good oiling.  Whenever I give it those three things, they last forever.  I can't figure out where they went wrong with their previous owners.  But once rolling, these typewriters are among Underwood's best.

Electric typewriters foreign and domestic--I include the earliest from the 1901 Blickensderfers (if you can find one) to the 1925 Remington electrics, the 1932 electric return only Burroughs, and the 1933 Electromatics to the late 1940s on up electrics.  Alot of purists who collect only manual typewriters will not touch an electric typewriter--mainly because they do not understand how they work, and believe them not to be true typewriters.  This isn't saying all collectors believe this, as I sure don't.  In fact, I believe the electric typewriters are a viable part of typewriting history--including even the electronic jobs up to the pre-computer word processors. 

So I end with a question:  What other machines can be included in the highly desirable list of typewriters a collector has Just Gotta Have?  I offered here a partial list, but, as a collector, I tend to go for most any brand--especially those machines that are specially equipped or have a very interesting typeface, or any ol' thing I haven't seen before.