There have some interesting looking seats over time, like the transcontinental sleeper berths back in 1934. To see photos of them:

A Brief History of the Airline Seat: From Wicker to Wow : News & Features : Conde Nast Traveler

1919: The world's first passenger plane, the 26-seat Lawson airliner stations wicker armchairs near it's cabin's celluloid windows.

1929: The Fokker F-32 flies in style with reclining seats covered in alligator skin, steward call buttons, and reading lights.

1930: As pure aluminum becomes more affordable, the Aluminum Company of America (Alcoa) introduces a light metal passenger seat around 1930, eliminating the warping, infestation, and combustibility issues of wooden chairs.

1934: Transcontinental services takes off, and American Airlines outfits the Curtiss Condor, an 18-passenger biplane that flies coast to coast in 24 hours, with sleeper berths.

1936: The Douglas DC-3 becomes the standard for passenger air travel and features chairs with foam-rubber cushions. Throughout the 1940s, aviation magazines display ads from foam manufacturers boasting "resilience and softness in one zephyr-light material."

1949: Pan Am launches spacious "sleeperette" seating and sleeping berths in its Stratocruisers, which offer overnight service to Europe.

1950s: The standard aluminum-frame seat, which all of today's coach seats are based on, makes its debut.

1989: Singapore Airlines outfits its new 747-400s with fully reclining seats in first class. Virgin Atlantic equips business-class seats with video screens; two years later, the carrier rolls out seat-back screens in all classes.

1996: British Airways introduces the first flat sleepers (and sleepwear), available only in first class. Four years later, seat-beds are installed in business class.

1998: British Airways spends $250 million to update its economy section, installingheadrests with wings to prevent "midair head flop." Singapore upgrades its first-class cabins, adding retractable desks stocked with stationery, and puts privacy screens in business class.

2002: Air Canada becomes the first commercial carrier to install airbags.

2007: Singapore Airlines outfits the first A380 super-jumbo with 12 first-class "suites"; each has sliding doors, a 23-inch video screen, a leather seat, and a standalone bed that can be joined with another to accommodate two people.

2010: Air New Zealand introduces the Skycouch, a row of three coach seats that transforms into a futonlike cot for two.