Hmmm... I love all the senshi pretty much equally, with Makoto only just topping the others.
So with that, means I undoubtedly love Haruka, and if I had to put them in a list of who I liked most to least, I feel like she would be close-ish to the top. I love her boyish attitude, she's laid-back, funny, flirty, and she's adorable and softens when she's with Michiru.
The only parts about Haruka that bother me was in the 90s anime she had a tendency to be flat out rude. When Usagi was crying Haruka would just be like "man up". That was annoying, although I don't fault her character for it entirely. The second thing that bothers me is that it's really hard to see Haruka without Michiru. Like when I think of Haruka it's hard to see her alone sometimes, which is unfortunate, as we all know they are separate and could be separate, but it's hard to think of her as much else other than "the one with Neptune". Same goes for Neptune, as well.