I knew Sailor Moon from the anime first as at the time I didn't know it was from a manga (in the 90's when I didn't have a computer and I was a kid).

I read through all of it after re-watching it and I still love it!
Story: Usagi discovers she is a Sailor guardian and from there, with the crew she gathered, she has to fight the evil organisations that try to take the Earth and ruin it with her magical powers!
I think the plot is good, there is hope, despair, love (all types!), peace and food and fashion, with some fights which is all good stuff.

Just a little warning for the ones who know the anime off by heart: the manga might seems shorter, but it is still very very good!

Art: Nothing to say about it. I just love it! It's full of imagination (the transformation, the powers the evil guys...) and it's well made. And the fashion! I would love such a collection of clothes!

Characters: The sailor guardians are strong-willed girls, even without their powers, they are still able to overcome their "weaknesses". They show that you can be beautiful, fashionable and still do whatever you wish to!
The main character is Usagi but I think there is a good share of focus on other characters as well, as we get to know some of their past and we can understand them better.
The evils ones are good in their job as well - they are bad and the further you go in the story, the worst they get!

I enjoyed every minute of it! I re-read it regularly. I laugh, cry, have my heart stop beating, I feel happy, sad each time I read it.
Overall, as you could guess, I think it is an outstanding work as it succeed to make me fell all these emotions every time I get back to it.