No 737-200.  Boooo.  Yes it was the backbone.  I, however, feel it lacks uniqueness.  It's a two engine moderately sized airliner.  

The 727 was unique in that it had three engines, swept back wings, was very fast, was somewhat more difficult to land than airliners of the day, handled like a fighter aircraft, and there were quite a few accidents due to pilots getting too footloose with her.

The 707 was unique in that it was a rather large airplane during its time (i think..), had four engines, and that test pilot Alvin M. "Tex" Johnson did a barrel roll in her during a demonstration flight over Lake Washington, Seattle, Washington USA.

The 757 is unique in that it is a rather large airliner with only two engines, sits relatively high off the ground compared to older airliners, and has newer systems and avionics.

Precision Manuals had made the 737-700 and -800 for FS9, those were good (i had the 700).

737-700 -800 are unique in that they have newer engines, very new avionics and equipment as well as winglets available as an option.

So there you have it, I don't see anything special about the 737-200 except that it was the backbone for the airlines for a very long time.

Well, thats just my opinion on the 737-200.  I could be totally missing something.  If I am, please let me know.  :)