Five TV series and 11 movies may be enough for some people, but the ones that were never brought to light still intrigue die-hard Star Trek fans. Read about 10 projects proposed between 1968 and 2005 that tried but failed to get off the ground for one reason or another. For example, Star Trek Phase II was supposed to be a TV series in the mid-1970s.
The series never got made because the TV network died, but the new characters were used for the first Star Trek film, and some of the episode plots were later recycled for the series Star Trek: The Next Generation. Read about the other projects at blastr. Link -via @johncfarrier
What it was: A sequel TV series. This series would've followed the now older (and thicker) crew of the USS Enterprise on an new mission into the unknown, along with a bunch of young new characters. They would've included Xon, a young Vulcan science officer (needed because Leonard Nimoy wouldn't sign on to the new series), first officer William "Will" Decker and Deltan empath Lt. Ilia. In addition to appealing to a younger (i.e. not middle-aged) demographic, the younger actors would've given the production more of a chance to continue if the original cast ever decided to leave.
The series never got made because the TV network died, but the new characters were used for the first Star Trek film, and some of the episode plots were later recycled for the series Star Trek: The Next Generation. Read about the other projects at blastr. Link -via @johncfarrier
As for the post, please note that there were in fact 6 Star Trek series, not five:
Star Trek - The Original Series (or just Star Trek)
Star Trek - The Animated Series
Star Trek - The Next Generation
Star Trek - Deep Space 9
Star Trek - Voyager
Star Trek - Enterprise
LLAP
PS. The cutting of Enterprise was a huge mistake.