Its amazing but it is suprising how many people who love Star Trek do not know these animated cartoons exist. I used to watch these as a kid back in the 70s, and i can still sit down and watch them today, and get the same enjoyment as i did back then.
Because the voices of the original series actors were used it gave the series an air of authenticity, you felt as though you were watching a proper episode of star trek as long as you able to see through the animated fascade.
These are well worth a watch and your kids may enjoy them as well.