A few years ago, I acquired a copy of a book entitled Window Seat, by Gregory Dicum (Chronicle Books, 2004), whose subtitle was "Reading the Landscape from the Air".  Further light on its purpose is shed in the introduction:  "This book is for anyone who has glanced out the window and wondered what the strange pattern on the ground is, or why that huge building is in the middle of nowhere.  This book is for the planetary explorer disguised in the ho-hum garb of the modern airline passenger."

Obviously this is dependent on having access to a window to view the outside world while in flight.  Today that is not necessarily a viable option for all passengers, when widebodied aircraft can have as many as ten seats across, and clearly, if you're seated near the center of this configuration, you may have a problem even seeing the nearest window, much less viewing anything out of it.

At the dawn of airlines, however, everyone had a window seat (of course, I'm referring to enclosed cabins, as opposed to open cockpit-style seating).  The first 'modern' airliner, the Boeing 247, carried all of ten passengers; five on each side of the aisle.  Each passenger sat in what was both a window and an aisle seat, and middle seats were still a bad dream away in the future. 

This had been the case for earlier predecessors, such as the Ford Tri-Motor.  Not only did you get a good view of the passing scenery (assuming that clouds didn't obscure it), but it was possible to check out gauges that were on inboard sides of the wing-mounted engines.  More interestingly, on a short flight, such as one could still experience in the early 1960s in Ohio's Lake Erie Islands, it was possible to note that the tires on the main (non-retractable) landing gear spun throughout the flight.

The DC-3 era introduced aisle seats to the mix, since they originally were designed with a 21-seat three-abreast configuration for 'day' use.  Post-World War two, many were converted to four-abreast, although with relatively large windows, even the passengers next to the aisle still had reasonable outside viewing opportunities. 

As aircraft grew larger, particularly in the postwar era, the four abreast configuration became standard.  But windows remained relatively large, whether in the four-engined "DC" series, or the smaller "DC-3 replacements" such as the Convair and Martin twin-engined aircraft.  Early developments of larger aircraft by both Douglas (the DC-4) and Lockheed (the early Constellation models) did have relatively small 'porthole' windows, but as both of these product lines advanced, they included larger windows with four sides.

The large turboprop era in the 1950s featured large piston-style windows on the Lockheed Electra, while the oval design utilized on the British Viscount was probably one of the best for external viewing of all time.  Even better was the application of this shape on the Fokker F-27, since the high wing meant that once airborne, all window seats, even the ones located abeam the wing, had unobstructed views of the terrain they were traveling over.

The full-scale implementation of the jet age in the late 1950s featured differing approaches.  The early Boeing and Convair four-engined jets had smaller, but closely-spaced windows, while the Douglas DC-8 retained the basic style of its piston-powered predecessor, the DC-7.  All of these aircraft also incorporated middle seats; on both sides of the aisle for the Boeing and Douglas products, while the Convair 880/990 were five-abreast aircraft, in the coach section.  Douglas later capitulated to the smaller/more frequent paradigm when it developed the DC-9, and all subsequent Boeing models, as well as those of Airbus, continue to follow it.  The advantage, of course, is that virtually all 'window' seats have some access to viewing; the downside is that the windows are generally smaller than in earlier times.

There have been exceptions, both good and bad, to this trend, however.  The French Caravelle, the first western twin-engined jet, had very distinctive windows that were essentially triangular in configuration.  On the downside, the Concorde's windows were tiny (and also, quite hot by the end of supersonic cruise), but external viewing was probably not the reason most passengers were using the type.  Both the Japanese YS-11A and the Canadair 50-seat regional jets suffered from having windows that were placed relatively low compared with seat height.  In the air, it was possible to get a some view downwards; trying to see much of anything during ground operations was best suited to children, or adults of considerably less than average height.

Of course, most of us will never be able to gaze out the best 'window seats' in the house, the ones with the forward-looking view, because they're in the cockpit.  I understand that some of these are better than others, also, however...