I know it's an impopular opinion, as most people go for the Doctor and Seven (and honestly, I really like both), but my personal favourite character has always been Kes. I was always curious about how she could find her place among the very military-like Starfleet/Maquis crew on board. The fact that her lifespan didn't exceed nine years was also intriguing. I liked her relationship with Neelix and Paris, and thought she was horribly underutilized in the third season when she grew her hair.
Furthermore, I am very fond of Neelix (!) and Chakotay. The first is often considered annoying, the latter boring. I never felt irritated by Neelix. I liked how he was the ship's cook, and thought he brought a lot of optimism to the quickly jaded crew. Chakotay I always thought was a pretty cool guy. Can't really explain it, but it's mostly has to do with the face tattoo.
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clarity of thought before rashness of action