After Voyager become "The Seven of Nine Show" all other characters aside from her and her two sidekicks (Janeway and The Doctor) were pretty much forgotten about. But then again, they weren't the best cast of characters: Chakotay, dull and uninteresting; Kim, boring; Neelix, loathsome.
Tuvok was a great character, a solid rock who started out as Janeway's friend and advisor, before fading into obscurity. Paris was a bad boy turned good, and had elements that I didn't mind though he too was at times bothersome. Torres was perhaps my favourite character in the series and was a breath of fresh air from previous Klingons, though after Seven came onboard, she went the same way as Tuvok. And then there's Kes, another character I really liked, that they got rid of for no reason. They took out a warm and compassionate young woman and brought in a stiff, cold and unpleasant one.
But that's just my thoughts.