Transport - we were meant to be travelling by rocket ships (UK to Australia in 30 minutes.) They could be built, there have been plans published, but no one wants to pay that much for the journey. Even Concord was too expensive to continue running.
Transport - we were mean to have air-cars or anti-grav cars. Again, the helicopter cars and autogyros are possible but their cost, and the impracticability of take-off and landing, means they are not in general use. Anti-gravity seems very unlikely anytime soon.
Atomic Power - planes, trains, ships, cars, refrigerators, almost everything was going to be run on the power of radioactivity and splitting the atom. Some of the ideas were really quite bizarre. It was going to cure diseases and was magical. The reality was that people were afraid of the weapons, for good reason, and disasters happened. Miniature power plants are not possible, and could they be safe? Then there is the question of the nuclear waste and the fact that Uranium is not a renewable energy source. It just never lived up to the exciting expectations.
Weather Control - we should only be having rain at night with long sunny days. No more floods or droughts. Perfect farming weather all year around. Yes, no clue where that idea went either. Wishful thinking? The one thing we have leaned is that nature cannot be tamed.
The old show UFO. Working Moonbase in the 1980s. Unfortunately - no. Similar remarks apply to the film 2001, unfortunately. A self-aware computer on board a manned Jupiter mission. [sigh]
Stories that presented the Soviet Union as a necessary part of the future such as 2001 and 2010, Jerry Pournelle's CoDominion and several of William Gibson's.
People get all sorts of kooky ideas when it comes to a newly available technology, but the fact is that both military and civilian nuclear powered ships exist, and the reason we don't use them on trains is because it is much easier to run the trains on electricity from a nuclear power station. Small reactors are used in space to power satelites and Skylab. The Russians have been running small 11 MW reactors since '70s in power plants.Atomic Power - planes, trains, ships, cars, refrigerators, almost everything was going to be run on the power of radioactivity and splitting the atom. Some of the ideas were really quite bizarre. It was going to cure diseases and was magical. The reality was that people were afraid of the weapons, for good reason, and disasters happened. Miniature power plants are not possible, and could they be safe? Then there is the question of the nuclear waste and the fact that Uranium is not a renewable energy source. It just never lived up to the exciting expectations.
Ones which depict the Earth's population reaching 7-10 billion and mass insanity or cannibalism resulting e.g. Stand on Zanzibar, Soylent Green, Larry Niven's U.N. birth lottery.