I'Borg and Descent were perfectly fine episodes. I'Borg kind of gets across the idea that every Borg is an ex-something . Strip away the cybernetics and the hive mind, and there still may be remnants of the original person behind there. Although I really didn't like everyone's mass conversion after having one conversation with Hugh. Star Trek's conception of proper military ethics sometimes puzzles me.
Descent was really more of a Data/Lore story and was effective on that level. It kind of have to be established that the whole collective wasn't effected by the events of I'Borg.
Full Contact was one of the top 3 ST films and I thought really presented the Borg well as a strong opponent. It took an entire fleet to defeat one cube(although shouldn't Picard's tactical evaluation of the Borg's defenses already be a matter of record?), and even the mighty Defiant was on the verge of destruction. The crew was unable to contain them once they were on board and had to resort to deciding to destroy the ship to overcome them. The drones weren't stooges walking into walls trying to obey the queens orders.
Voyager? You've got to be kidding.