Most known is very subjective, but the three best known for me are:
The Stingray Nebula (Hen 3-1357) is a planetary nebula. (The youngest known).
The Ant Nebula or "Chamber of Horrors" [See Link] can be found in the constellation Norma [See Link]
Andromeda, Milky Way These are galaxies ^ Orion Nebula Eagle Nebula
Sagittarius is a constellation which contains several well-known nebulae. These include the Lagoon Nebula (Messier 8), the Omega Nebula (Messier 17) which is also known as the Horseshoe Nebula or Swan Nebula, and the Trifid Nebula (Messier 20).
The two most well-known nebulae are the Orion Nebula and the Crab Nebula. The Orion Nebula is one of the brightest nebulae and is visible to the naked eye, located in the Orion constellation. The Crab Nebula is the remnant of a supernova explosion observed by Chinese astronomers in 1054 AD, located in the Taurus constellation.
Two well-known nebulae are the Orion Nebula (Messier 42) and the Crab Nebula (Messier 1). The Orion Nebula is a diffuse cloud in the constellation Orion, visible to the naked eye, while the Crab Nebula is a remnant of a supernova explosion observed in the year 1054.
The Stingray Nebula, the youngest known planetary nebula.
The Tarantula Nebula, also known as 30 Doradus, is one of the largest and most active star-forming regions in our nearby universe. It is located in the Large Magellanic Cloud galaxy, around 160,000 light years away from Earth. The Tarantula Nebula is roughly 1,000 light years in diameter.
The nebula you are referring to is likely the Swan Nebula, also known as the Omega Nebula. It is a famous emission nebula located in the constellation Sagittarius. The name "Swan Nebula" comes from its resemblance to a swan when viewed in certain images.
The orion Nebula
Another popular nebula is the Eagle Nebula, also known as Messier 16. It is located in the constellation Serpens and is famous for the "Pillars of Creation," which are towering columns of interstellar gas and dust where new stars are forming.
The Nebula Theory is also known as the Solar Nebula Theory. It is a widely accepted model for the formation of our solar system.