Name four airliners that changed Air Travel.?

I am going to list my favorite four, but you may have others.

1. Boeing 247, 1933. First modern airliner, with low wing, two engines, and fully enclosed cabin. Carried ten passengers.

2. Douglas DC-3, 1935. First truly practical airliner that could pay for itself hauling passengers alone. Early versions carried 21 passengers, but later models carried up to 28.

3. Lockheed Constellation, 1945. First practical long-range pressurized airliner, and first airliner with true transatlantic capability. Led the way to other pressurize long-range prop airplanes, such as the DC-6, DC-7, and Stratocruiser.

4. Boeing 707, 1957. First truly successful jet airliner to enter regular service in both transatlantic and domestic service. Led to one of the most successful airliner families in airline history.

You might have other favorites that belong on this list as much as these four. Please share them and tell why they were important.
Technically the Cessna 152 and Space Shuttle are not airliners. Interestingly enough, the 152's larger sister, the Cessna 172, is certified to be flown as an airliner, however. And the Space Shuttle has carried commercial payloads.

The Boeing 737 has a legitimate claim to changing air travel, as referenced. It is an international favorite and the backbone of low-cost airlines such as Southwest.

The Concorde hasn't changed air travel that much, although it is to date the only supersonic airliner to be mass produced and to be flown in scheduled service. Its operating costs have kept it from being available to the masses who travel. A revolutionary design that could have a future impact on very fast airliners, and that could be a true legacy. We'll have to wait for that development, however.
Without listing them by name, I can think of several other airliners that could be added to this list. Each made a contribution to commercial aviation that was significant. When I close this question, in a day or so, I will list them if they haven't already been included.
Here are a few other noteworthy airliners that changed air travel.

Convair 240-440 series twins, 1948. These airliners were ahead of their time, pressurized, fast, able to handle short runways. They couldn't quite replace the DC-3, but they were great on their own.

Douglas DC-4/DC-6/DC-7. 1943. Same basic planform and wing, but each model added capacity and performance. DC-6 and DC-7 were pressurized.

Douglas DC-8, 1957. Rival to Boeing 707, but not able to match it in early sales. Redesigned as a stretch version and became predecessor to jumbo jets.

Douglas DC-9, 1966. First American short-haul jet. Led to current MD-80 and MD-90 families of jets. These truly brought jet power to feeder lines and regional airlines.

These are all American designs. Some fine aircraft were also contributed by foreign manufacturers.
Some foreign airliners that played a role:

France, Caravelle, 1956. First true short-range jet.

Britain, Viscount, 1949(?). Four-engine turboprop. Popular in Europe and also in North America. Followed by Vanguard, both from Vickers.

Britain, Bristol Brittania, 1954 (?). Big turboprop, an early jet-powered transatlantic airliner. Followed by Canadian Canadair CL-44.

Japan, NAMC YS-11. Twin turboprop.

Europe, Airbus A-300. First jumbo twinjet reliable enough to fly the Atlantic.

Also, two American birds, the DC-10 and the Lockheed L-1011. Tri-jet jumbo airliners.

There are still other airliners worthy of note. Fokker and Ford trimotors, for example.

King Fisher, 2008.

1. The DC-3 for obvious reasons as a great work horse for so many years.
2. The SST because it brought the speed to air travel.
3. The Cessna 152 because it allowed common people to learn to fly and go on to become pilots of the airlines.
4. The Space Shuttle because it has ushered in an era that will eventually lead to space travel by the people of our planet.

Can only think of 2 more not already mentioned...

+ Boeing 737. The best-selling airliner of all time, the workhorse of Southwest and Ryanair, has made air travel affordable for the masses.

+ Concorde.

The Boeing 747 as it became the largest passenger carrying aircraft. It allowed for more passengers to travel farther distances. Was important to Pan Am's fleet.

The Boeing 757/767 since they were the first aircraft to be ETOPS certified. Also due to the similarity of the aircraft, a pilot doesn't need much more training to be able to be certified to fly both types of aircraft.

The Boeing 787 since it is the first aircraft made entirely of composite material. Also the aircraft comes with bigger windows and the lighting will help passengers get over jet lag better.

Comet. Even though it ended up being extinct, it was the first passenger jet airliner.

Airbus 320 was the first aircraft to use fly-by-wire technology.

Bombardier CRJ-100. A lost cost aircraft that does not carry a lot of passengers but is not a turbo-prop. Since it is a jet, the aircraft flies above the clouds versus below so the flight is smoother. Also helped paved the way for regional airlines to switch from turbo-prop aircraft to jets.