Monica

RACHEL: So why don't you go talk to him?
MONICA: [sarcastically] Oh, yeah!
RACHEL: What? So you go over there, you tell him you think he's cute. What's the worst that could happen?
MONICA: He could hear me!

Today we're gonna talk about Monica, a complex woman with a strong personality. Monica is comically obsessive about her apartment and loves cleaning. This personality trait becomes exaggerated as the series progresses.

MONICA: "Usually when I'm this anxious, I clean!"

And she's also highly competitive and bossy. She orders the events run on "military time".

MONICA: "Rules help control the fun!"

Knowing all this about her, you would think "who the hell would be friend of that crazy woman?", well let's see her story:

Monica initially shared her apartment with Phoebe but she moved out, worried that their friendship would suffer, due to Monica's obsessive tidiness. Later, when Rachel appears again in her life, Monica accepts to live with her, although back in school Monica had hate Rachel. About her relationship with Chandler, Monica and Chandler are at the beach when it is revealed that if Chandler was the last guy on earth, Monica would still be unsure about dating him. But, a couple of years later, in London, Monica was mistaken for Ross's mother and Chandler comforted her, saying she was the most beautiful woman he had ever seen, so they slept together the night before Ross's wedding. Chandler moved in with Monica in Season 6 and got engaged in the season finale, marrying in the Season 7 finale. In the Series finale, they adopted twins, and so the "baby fever" that Monica had could finally end.

During the series, it is revealed that Monica had been obese, weighing 255 pounds in high school. Ross explains in a very clear way who it was living with his fat sister: "I grew up with Monica! If you didn't eat fast, you didn't eat!". It is also revealed that Ross had a therapist due to a recurring bad dream, which was that Monica was going to eat him.

Monica works as a chef, and, as with most areas of her life, she is obsessive and competitive.

(Chandler and Phoebe look bored to death. Monica scores and laughs)

MIKE: Ok, so it's a tie again, 41 to 41.

CHANDLER: (exhausted) Ok, look! Enough is enough!

MONICA: No, I have just to have two more points to beat him!

CHANDLER: Monica, that was also true an hour ago! I mean, please, look at you! Your hand is blistered, you can barely stand, your hair is inexplicable! Ok, you've already proven you are just as good as he is, now we've missed our dinner reservations, so now let's just go upstairs, order room service, take a shower and shave your head!

MONICA: I can't just walk away! I've put in four hours!

CHANDLER: But...

MONICA: Look! You knew this about me when you married me! You agreed to take me in sickness and in health. Well, this is my sickness!

CHANDLER: What about the obsessive cleaning?

MONICA: That's just good sense!

Her catchphrase is a loud, excited and exaggerated I KNOW! (but I guess YOU KNOW!)
Personally I think she's great, but also less funny than the others... I don't know... I like her but... maybe I like her because Chandler likes her!