Is this a serious question?
Which should you watch?
One of the greatest and most popular sci-fi shows of all time, that re-launched Star Trek on TV, resulted in a film series, enabled Star Trek to become culturally popular for a while in a way it never had before. A mature, serious show that relied on smart writing and that could probably have gone on for as long as it wanted to? A show worthy of the legacy of TOS.
A show that was so unpopular it limped along for four seasons before becoming the first Trek since TOS to be cancelled. A show that relied on catsuits and tired plots. A show with an incompetent captain and a horribly conceived Vulcan character, and an ignored supporting cast. A show that ran Trek on TV into the ground.
When given the choice between an upscale gourmet restaurant and taco bell(assuming you're not paying) do you usually take a lot of time to consider the choice?