I actually really like the nine part finale of DS9, esp the Dukat vs Sisko ending. While I like the majority of the series, the last two seasons are the seasons I typically rewatch, and then selectively go back to the previous seasons, as they're not nearly as good.
As for Voyager, it's mostly a microwaved, soggy mediocre version of The Next Generation (the show largely is TNG if that show had all its good characterization, intelligent writing and novelty sucked out) , it'd be totally forgettable and skipabble if not for the EMH and Seven of Nine, who are the only interesting characters on the show. It does have a few stand-out episodes but the show is completely devoid of character development (outside the EMH and Seven of Nine), interesting ideas and entertainment (the show can be unbelievably boring even for generic Star Trek) and the few good episodes (like Scorpion or Timeless or Blink of an Eye) don't make up for seven seasons of largely flavorless oatmeal.
A major reason (beyond the executive meddling which did not exist on TNG and DS9, a major reason those series are so much stronger) is because Brannon Braga and Rick Berman (the showrunners) were miffed they couldn't do their exact vision, so they got burned out and put minimal effort in the show. Pre-Voyager Braga was (largely) a good writer, and pre-Berman was actually (mostly) a positive force on Trek, but by Voyagers time, they got crushed by executive meddling, and TNG's success also taught both to be very conservative with writing (as in they shouldn't deviate from the TNG format at all), so they ended up just churning out mediocre pale imitation crap, that got decent ratings so no one complained. When the exact same situation happened on Enterprise however, the show got shitcanned fairly quickly (by Trek standards anyway, it's amazing it got four seasons..) and they lost control of the entire franchise (thankfully). Ronald D Moore actually moved to Voyager after DS9 ended but left after only a few weeks because he was disgusted with the environment and Braga and Berman. Add all that to the often mindless stupidity of Voyager, and overall it's just not a very good show. I still can't decide if it's actually worse than Enterprise, which of course is also pretty bad.
TL;DR Voyager is a souless, lifeless version of TNG, and Enterprise starts off as a retarded version of Voyager, and then slightly improves right before it's shitcanned. Stick with TNG and DS9, the only good Treks, and if you're adventurous, go into the TOS minefield. VOY and ENT will make you wonder why you're watching Star Trek to begin with.