Alien Force is a subtheme of Ben 10 that was introduced in 2010 and currently consists of 6 sets. All sets were released in 2010. As of today, the average annual growth of all the sets in Ben 10 Alien Force is around 7.0% per year. The current value of all sets in new/factory sealed condtion is $288.61.
Most valuable LEGO Alien Force set 8517 Humungousaur - $60.93
Largest LEGO Alien Force set8410 Swampfire - 22 pieces
Most owned Alien Force set8409 SpidermonkeyLEGO Ben 10 was a collaboration between LEGO and Cartoon Network in 2010 and was based on the Alien Force series. It was an unsuccessful theme commercially at the time and was discontinued in the same year, in fact, the theme is considered by some as the most unpopular LEGO theme of all time. The sets where based on the BIONICLE parts and each set is an action figure version of one of Ben's alien forms. The Ben 10 theme was revealed at about the same time that BIONICLE was being wound down and did feature an improved ball-and-socket joint.