Blakes 7 - it ended with virtually all of the cast dying (sorry if anyone hasnt seen season 4)
Enterprise - i detested season 3 with a vengence but i felt season 4 was a return to trek and respected the trek lineage left by previous series, i felt that if season 5 were made they could have done the romulan war.
Firefly - It was axed just as the writers started developing the characters
Farscape - although the mini series try to give an end to the series it left me feeling unsatisfied and i thought there was no need to kill off any of the main characters
I thought the original reason the 'jumpsuits' (onepeice, season 1/2 uniforms) were replaced because some of the male leads started getting back pains from the uniforms, thats why they were changed to 2 peice