1. Star Trek. Yes, that's right, it's called Star Trek. It is Star Trek. It's the only Star Trek. The rest are just pale (often downright bad) imitations of a classic sci-fi series in its rightful historic context as the clear-cut best of the entire franchise. Anyone who says otherwise is just plain, old-fashioned, wrong; and most likely the result of parentage of a questionable nature.
After this, we come to "which is least bad of the dredge unfortunately spawned by such a great show?"
2. The Next Generation. Not as bad as the rest, but far too sterile, with caricatures instead of characters. In fact, the android Data was the most human of the crew. Except for Riker, who was not that bad.
3. Voyager/Enterprise. At least now there are humans back on the show. Unfortunately, that's all that can be said as a positive.
4. Deep Space Nine. Not even Star Trek, I don't care what the title says. Soap-opera garbage which should've aired immediately prior to Days of Our Lives.