Captain Janeway was an okay character. She struck me as a female Picard, which, frankly was boring. It would have been better had she been played more like Kirk, especially considering they're stranded on the other side of the galaxy.
I think that they could have done better with Chakotay. He was a stereotypical Native American, the only way they could have made it more so would have been to make him an alcoholic, though then the creators would have faced charges of racism. Almost every episode that featured him had him going on a vision quest. At first it was an interesting, but then they used it so much that became silly.
Of all the characters, the Doctor had to be my favorite. He's the only character who experiences any actual growth as the series runs it's course, with the only other exception being Seven of Nine.
Seven of Nine was the most interesting of the characters, and not just because I found her the most attractive. She brought conflict onto Voyager and served as a great foil to Captain Janeway.
Tuvok was a Vulcan, and played his role well. I enjoyed the conflict that arose between him and Neelix. When the two characters became merged in a transporter accident, I found that show particularly interesting, though there weren't really any lasting ramifications from the event, which there really should have been. Also in this episode, Janeway breaks character, which seemed to me a good reason why she should have been more like Kirk in the first place.
My biggest annoyance with the series was B'Elanna Torres. She's supposed to be a Half-Klingon, known for her fierce temper. Instead we get a whiny bitch. There wasn't an episode she was in where she didn't ruin it for everyone who was having fun. Her relationship with Tom made no sense whatsoever, though I've seen this happen in real life, so it was at least believable.
Neelix was a good addition to the crew, particularly since he balanced Tuvok's character. The thing that ultimately made no sense, however, is his relationship with Kes, or more specifically, the way the writers ended it. Kes gets possessed, and while possessed, ends her relationship with Neelix, but when she returns to normal, they stay broken up, and no explanation is given. The audience is just left wondering what happened.
I think Kes was a much better match for Tom, and the show really should have pursued that path, rather than B'Elanna. Unfortunately, the actress, Jennifer Lien was given the axe later on (they should have gone with B'Elanna, as Seven could have easily replaced her in Engineering, or even Harry Kim, who was easily the most boring of the Voyager crew.) Kes was a character that had real potential, but the writers didn't develop her well.
Star Trek Voyager as alright for a Star Trek series, it had potential to be a lot more, but ultimately failed to impress. Next up, Star Trek Enterprise.