I would have to say that the last season, season 7, is my favorite Star Trek Voyager season.   I never got to see it when it originally aired, and it also has two of my favorite time travel episodes: Shattered and Endgame.

In Shattered, an energy field leaves sections of Voyager in a different time periods, and, it i s up to Chakotay, who was not affected by the energy filed, to put Voyager back together. In End Game, an older Janeway travels to the past to help Voyager get home.