One thing I can say is avoid the episode Threshold at all costs. It will make your head explode. It started off ok and then went very, very wrong.
Voyager's ratio of good to bad episodes is definitely below 50% but there are some good to great episodes scattered thruout it's run. Some of my Voyager favorites are Relativity, Distant Origin, Dreadnaught, Message in a Bottle, Drone, Timeless, Dragon's Teeth along with Year of Hell which should have been how the ship looked after a few years lost in space, kind of like starship Equinox from the Equinox episode.