Voyager seasons
After Star Trek TNG ended there was a desire to create a new show to supplement Star Trek DS9. One of the concerns about DS9 was that it was a potentially disastrous experimental format for a Star Trek show, seeing as how they were not "boldly going" anywhere, so Voyager was created to fill the "boldly going" void that TNG left in the Trek universe. But so as not to be a mere rehash of TNG's adventures with a new cast, the idea behind Voyager was that it would be a crew that was lost on the other side of the galaxy. Their mission throughout the show would be to find a way home, putting a different spin on chronicling the adventures of a Federation starship. Voyager had an absolutely wonderful premise. At the beginning, it seemed to live up to TNG completely, as well as introduce new interesting details of its own. The crew was a mix of friend and foe, the ship itself was newer and more exciting than the Enterprise-D, yet also not designed for long journeys, and resources were scarce. It had all the ingredients necessary to create good drama out of a Star Trek show, with just enough exploration potential to keep fans of the TNG formula happy as well.
However, the show was taken in directions the fans neither expected nor wanted on numerous occasions. The first major problem was the trivialization of the trip itself. Finding resources and fuel never turned out to be a major recurring problem. Everybody seemed to live in almost as much luxury as the Enterprise-D except on a few isolated occasions. The next annoying problem was the trivialization of the Maquis. There were virtually zero real Maquis-Federation conflicts in Voyager. In fact you could count them all on one hand. Instead everybody just became friends right at the beginning. A nice sentiment maybe, but it wrecked quite a bit of the show's dramatic potential. The thing that was supposed to separate Voyager from TNG was the scarcity of resources and the internal crew conflicts, but both were downplayed rapidly. As a result Voyager became as much like TNG as possible, save only for the primary mission of trying to find a way home with a side of exploration instead of simply pure exploration. In fact Voyager was in many ways better than TNG at implementing the TNG formula, as there was more serialization and the stand-alone episodes were generally better executed.
But despite better serialization compared to TNG, Voyager's serialization still left much to be desired. From day one with Voyager being lost in the delta quadrant, the writers and fans alike both knew that a conflict with the Borg was inevitable. Borg space was surely between Voyager and the Federation as was established in TNG. At first this was executed extremely well. Voyager's season 3 finale and most of season 4 were some of the best stories Star Trek ever told, airing right alongside DS9's magnum opus Dominion war arc. While Voyager's overall quality continued to remain high until it ended, the initially awesome Borg, Species 8472, and Hirogen arcs were unfortunately watered down significantly. Both Species 8472 and the Hirogen were entirely trivialized just a few episodes after their awesome introductions and the Borg were taken in unfortunate directions as well on several occasions. Nearly every Borg episode after Dark Frontier was annoying because Borgbuster Janeway was wiping the floor with Borg, trivializing them as well. By the end of season 5 the show's attempts at or avoidance of arc-driven storytelling were just becoming ridiculous. The introduction and quick destruction of the Equinox was a big missed opportunity, Unimatrix Zero was underwhelming too, and the series finale Endgame was a fun episode but a disappointing finale. A better Voyager show would have intensified and condensed the Maquis and Kazon/Seska arcs into the first season along with the Borg, Species 8472, and Hirogen arcs into seasons 2 and 3. Seasons 4 and 5 should have been Voyager's homecoming and participation in the Dominion war, and seasons 6 and 7 could have been more traditional exploration TNG-style possibly also eventually dealing with an all out Borg assault on the alpha quadrant (perhaps in response to Janeway having stolen Borg transwarp coils to reach Earth, as opposed to the deus ex machina way they actually reached Earth in Endgame), giving Voyager a way to end in an epic way, instead of with a whimper.
But also like DS9, despite clear (though more severe) issues with the way the various story arcs were executed, Voyager managed to produce numerous utterly fantastic, memorable episodes. Episodes like Death Wish, Scorpion, Year of Hell, Timeless, Dark Frontier, Relativity, Tinker Tenor Doctor Spy, Life Line, and perhaps the best and most underrated episode of the series Distant Origin make the series among the best Star Treks, successfully rivaling TNG. In addition to numerous memorable episodes, Voyager had one of the most memorable casts as well. Colorful characters like Janeway, Tuvok, the doctor, and Seven of Nine gave the show a special place in Star Trek's chronology, much like Picard and Data's contributions to TNG, or the contributions of Odo, Garak, Weyoun, and Dukat to DS9. Voyager also had the best executed humor of any Star Trek show.
People are well within their rights to criticize Voyager for not living up to its potential. It had the potential to be every bit as awesome as DS9, but with more diversity, more exploration, more serialization, and more depth. Voyager could have been a truly epic story if the writers had taken advantage of the critical acclaim DS9 was receiving for its arc-based storytelling. But I suspect fear of transforming Star Trek from a formulaic, light-hearted show into a continuing dramatic story was quite strong. For all DS9's critical acclaim, it was a story that would easily lose viewers who didn't keep up with it, whereas Voyager and TNG were easy to jump into at any point. Measured against the formulaic standards set by TNG, Voyager was a very well executed show. But measured against the emerging third generation of space opera which DS9 was dabbling with during its final years, Voyager falls short; a regression backwards from DS9. Indeed, Voyager"s disappointing treatment of its arcs and disappointing series finale were the beginning of a long decline for the Star Trek franchise. While Voyager was still popular enough to end gracefully, the fans were beginning to get tired of the old formula. The end of TOS, TNG, and DS9 left fans wanting more, but Voyager signaled the end of a tired formula. A better executed version of the tired formula, but still the same formula.