Pilot you really wished it became a series

[Bakuma1997]

Pilot is the basically a prototype for a series, be anime, live action or cartoons, while some succeed, some aren't so lucky, showcase yours
While using the Cartoon preflix, anime and Live action applies

Mine must go to this one, especially in a age that ensued the only thing that changed was the shape of the phones

 

[Guinea]

One of the most OP DC characters never got his own show and that still makes me sad:

Edit- Oh, and while this show never even had a pilot episode, and is currently in limbo with no hope to ever being made, I'm sad that the Final Fantasy 9 anime never came to be. It was going to be called Final Fantasy IX: The Black Mages' Legacy, which featured Vivi's children growing up and saving the world. I hate Square Enix sometimes.