Mercury in a graceful pose
Sailor Mercury - Mizuno Ami

Real Name: Mizuno Ami 
Name meaning: beautiful center of water 
Birthday: September 10th 
Zodiac sign: Virgo 
Height: 5'2" 
Senshi Position: Inner Senshi
Element: water
Fighting Style: defensive
Secret Weapons: none
Favorite Color: aquamarine 
Hobbies: reading, playing chess 
Favorite Subject: math 
Worst Subject: none 
Favorite Food: sandwiches 
Favorite gemstone: sapphire 
Family: both parents alive, but separated 
Dream: to be a doctor 
Seiyuu: Hisakawa Aya

By the standards of most Japanese men, Ami is the ideal Japanese woman. She's quiet, submissive, and studies a lot. That's probably why she was the most popular senshi in Japan when SM first came out, and why she has so many male followers. If she were married, she'd probably be the type of wife that just sits around doing housework, and does whatever her husband tells her. Which is obviously why any guy would want her as a wife. ^-^
But she probably wouldn't just be her husband's puppet. She'd have a job too. See, Ami is very intelligent, and her IQ is supposedly 300 or something super high like that. She wants to be a doctor, because that's what her mother was, and because she wants to use her intelligence to help other people. That's why she studies so hard. She wants so badly to get into a good college, she even goes to a juku (cram school) after her regular school every day to study (which DiC refered to as computer class, probably because it was an aspect of Japanese tradition that they didn't feel like explaining). She also wants to please the people around her, like her mother and the senshi. Her dad was an artist, and one day he just...left. He still kept in touch with the rest of the family, but he never did come back.
Ami is, as I mentioned before, quiet and submissive. Before she met the senshi, she never really had any friends. If she were left in charge of the senshi, she wouldn't have any idea what to do. She's just used to other people dictating what she does. She's the brains of the senshi, and can always figure out the answer to any logical problems they might encounter. She has a little miniature computer that has her symbol on it, and it sorta looks like one of those electronic organizers. But it's not, it helps her figure stuff out. So does her visor, which is a pair of goggles type things that appear when she presses her earring.
Ami temporarily had a sort-of-boyfriend, Urawa Ryo. He only showed up for two episodes before he had to move away, though, so they never really did anything. Of course, he wasn't in the manga, so he didn't show up very much in the anime either. Though they liked each other a lot, Urawa-kun thought he didn't deserve her because she was so smart. He was the only one who could beat her on exams, but only because he was psychic and could see the answers in advance. Then in her SuperS special, Ami-chan no hatsu koi, she liked another guy, Mercurius, because he actually did beat her on the exams. But since he was using a pen name, she never really found out who he was. Oh, and she got a love letter from him and broke out in hives because she just can't deal with love letters. *g*
Ami's motto is "Pure, honest, beautiful," and she certainly lives up to that. She's very modest, passive, and kindhearted. As for honest, she definitely is. She always tells the truth, unless of course it would hurt someone's feelings. I guess she is the kind of girl that any Japanese (or maybe American) guy would want to marry, but even so, she's a bit boring.

 Mercury Power, Make Up
Ami's transformation phrase into Mercury in the first season.

Mercury Star Power, Make Up
What Ami says to transform into Mercury starting in R.

Mercury Crystal Power, Make Up
What Ami says to transform into Super Sailormercury in SuperS on.

Shabon Spray
It literally means soap spray...which it is.  What Mercury says to sort of cloud the area over with blinding bubbles.

Shine Aqua Illusion
Mercury takes a drop of water and sprays it around, turning everything to ice.

Shabon Spray Freezing
Same as Shabon Spray, only the bubbles freeze.

Double Shabon Spray Freezing
A heightened form of Shabon Spray Freezing, or something.

Mercury Aqua Rhapsody
Mercury says this and plays her Aqua Harp.  Streams of water shoot out of the harp.

 Henshin pens
3 different ones: the first one, the one she gets with her R power-up, and the one that turns her into her super form.

A communications device that is disguised as a calculator that all the senshi have.

Communicator watch
A watch that sort of takes the place of the communicators that all the senshi get in R.

Something that just Mercury has that appears when she presses her earring.  It lets her see things that she couldn't normally see.

Mini computer
A little blue device that looks sort of like a compact that has the Mercury symbol on it.  It's actually a miniature supercomputer that Ami uses to figure things out.