If you want to talk about TV shows that really left a mark on sci-fi, you can’t skip Star Trek: The Next Generation. It was a game-changer when it hit screens back in 1987.

Denise Crosby left Star Trek: The Next Generation because she was felt she had too little to do as Lt. Tasha Yar. After TNG 's first few episodes, Yar was largely regulated to the background while ...