Tsukino Usagi is the champion fighter for love and justice, Pretty Soldier Sailor Moon. In the first couple of seasons, she is repeatedly referred to as a clutz, ditz, and crybaby. Although throughout the series she matures, she can still have her moments. In the very first episode of Bihoujo Senshi Sailor Moon, Usagi discovers her identity as a Sailor Senshi by rescuing a cat [Luna] from being tortured by a group of young boys. Luna gives her the transformation brooch, and from then on she started her double lifestyle going from a normal teenage girl to an evil-vanquishing heroine.
         It is revealed soon after that in Usagi's past life, she was the Princess Serenity of the Silver Millenium Moon Kingdom, and her lover was Prince Endymion, [Mamoru] from earth. Her mother was Queen Serenity, the ruler of the universe. The main source of power was the  ginzuishou, or the Silver  Crystal. The Moon Kingdom was destroyed, however, by Queen Metallia and Queen Beryl of the Dark Kingdom. They attacked in order to gain control of the universe. During the battle, Princess Serenity, Prince Endymion, and the senshi [at that time they were the princesses of their respective planets] had all been killed. Queen Serenity, after realizing that the kingdom could not be saved, used the last of her strength by sending Usagi and the others [including Mamoru and the cats] to the future, to live a happy life on earth.
        In Usagi's future life, she is destined to follow Queen Serenity, and become Neo-Queen Serenity, and rule Crystal Tokyo, a future Utopia, with Mamoru. They have a daughter named Chibi-usa.
        Usagi is kind-hearted and pure, and would rather save someone from evil rather than kill or even harm them. She would do anything, even to the point where she would give her own life, to save someone who had been influenced by evil. [If you noticed, she never killed anyone in the S series. All the villains were killed by each other, and it is unknown whether it was actually she or Saturn who destroyed Master Pharoah 90.] In the first season, she tried to save Nephrite's life after he changed, in the second season she cried when both Safir and Demando were killed. In S, she refused to kill Mistress 9, even if it meant the destruction of the earth. In the fourth season, rather than destroy Neherenia, she was left inside the mirror realm. And, finally, in Sailor Stars, Galaxia was healed instead of killed, even if Galaxia had beforehand destroyed all of her friends.

Attacks

Moon Prism Power, Make-up: The transformation phrase to become Sailor Moon using the brooch.
Moon Tiara Action: Her first attack where she uses her tiara like a frisbee.
Moon Tiara Stardust: She only used this attack once, where her tiara sprinkled dust over children that had healing properties.
Moon Healing Escalation: Her attack using the Moon Stick.
Moon Prism Power: The attack where she uses the ginzuishou (this is also the one that caused her death at the end of the season.)
Other Attacks:
Sailor Moon Kick (like Sailor V's, I think this one is used only in the manga. Maybe once or twice in the anime.)
Moon Power, Ni Nare (the phrase she calls out to activate the transformation pen, to disguise herself as other people.)

Moon Crystal Power, Make-up: Her phrase to transform into Sailor Moon using the crystal compact.
Moon Princess Halation: Cutie Moon Rod attack.
Moon Crystal Power: The phrase she uses to destroy Master Pharoah 90 and to heal the Ayakashi Sisters.
Other Attacks:
Body Slam

Moon Cosmic Power, Make up: Transformation phrase to turn into Sailor Moon.
Crisis Make Up: Sailor Moon's power boost to transfrom into SuperSailorMoon using the Holy Grail.
Moon Spiral Heart Attack: Spiral Heart Moon Rod attack.
Rainbow Moon Heart Ache: Second attack using Spiral Heart Moon Rod.

Moon Crisis Make up: Transformtion using Pegasus' power
Moon Gorgeous Meditation: Using the Moon Kaleidoscope, this is her attack.

Moon Eternal Make up: Transformation phrase for Eternal Sailor Moon.
Starlight Honeymoon Therapy Kiss: A healing power attack.
SilverMoon Crystal Power Kiss: Eternal Sailor Moon's attack, given to her by ChibiChibi.