This is a story that only gets stronger the more desperate everyone gets, from guest star Kurtwood Smith to Chakotay, who almost gets points as lead character to Tuvok bonding with Seven to Janeway with an awesome one-liner to close out the experience.
"Year of Hell" is essential viewing for Voyager, and it's a rare two-part episode in the franchise where the conclusion is completely worthy of the set-up, not to mention the story continuing seamlessly from one half to the next, without need for significant tinkering on what exactly you're supposed to be caring about.
Whereas there are more clear standout characters in this half, it's still an ensemble effort, and therefore most clearly enjoyed for all of them. If you're a fan of this series, you have to see this one.
Franchise * Series * Essential * Character
Memory Alpha summary.