The most famous space voyage had to have been Apollo 11, where Neil Armstrong and Buzz Aldrin walked on the moon.
There are a few reasons that it is the most famous, number 1 being the fact that it was the first voyage to be televised. Almost every person alive in America at that time was watching them walk on the moon. They even brought TV sets into schools and had all of the kids watch the moon landing from one TV set.
Another reason it is extremely famous is because it caused The United States to take a giant leap ahead of the Space Race.
Finally, the last and most important reason is simply because they were the first men to ever walk on the moon.