Seven was an interesting character. Her quest for humanity was interesting because she wasn't entirely comfortable with the steps and wasn't at all eager compared to eager beaver Data & the Doctor. She also regularly challenged Janeway (which was probably one of the aspects of finding humanity/being deprogrammed from the cult of the Collective that she happily embraced) which was something people wanted the Maquis to do more of. She also took over Neelix's role as Sacagawea of the Delta Quadrant, using the Borg's knowledge of space to explain races or phenomena in different episodes. If things went differently, she could have been the cook, using all the recipes the Borg have assimilated to cook for Voyager a wider culinary selection than Annorax's culinary museum ever could, and she could have improved the efficiency of the cooking appliances with her Borg knowhow.
And "Latent Image" *was* Season 5. Aired January 1999.