What are the best quotes to use for juror 3, 8, and 10 to make inferences about their personalities and attitudes?

In Twelve Angry Men by Reginald Rose, 12 jurors sit in a hot room and debate the fate of a young man on trial for the murder of his father. Though 11 of them initially vote to find the defendant guilty, one man, Juror Eight, argues that they should not. He proceeds to convince the entire room that they should eventually change their votes and acquit the young man.
Quotes from Roses's play show the character of each man, what interferes with his personality and attitude, and what is required to change his perception of the case. As they take votes for guilt or innocence, the tallies slowly change.
To better understand which quotes best represent the jurors—and what affects them personally—it is important to know who the jurors are. Understanding each character will make it clear why certain arguments or pieces of evidence interfere with their decision-making; it also helps to show why their attitudes are or are not changed by certain influences.
Juror Three is the last juror to change his vote. His character description says he is a forceful, opinionated man who is a bit sadistic. He does not like hearing other people's opinions and often pushes his own opinions onto others.
Juror Eight is the one who did not vote guilty in the initial vote. He is described as quiet and thoughtful—the kind of person who wants to see every aspect of a situation before passing judgment. He is extremely just.
Juror Ten is angry and described as bitter. He is also a bigot who does not see other people as valuable. His character description says he "has been nowhere and is going nowhere and knows it deep within him" (5).
First, consider Juror Three. Juror Three initially gets upset with Juror Five because he mistakenly believes that Juror Five is the one who changed his vote to not guilty on the second vote. This shows that he does not value the opinions of others, but this is just the tip of the iceberg. There are a few important things to consider about Juror Three that show why it is difficult for the rest of the jurors to sway him.
Juror Three is initially biased against the defendant because of his relationship with his own son. He explains it to the other jurors, saying,

You’re right. It's the kids. The way they are—you know? They don't listen. [Bitter] I've got a kid. When he was eight years old, he ran away from a fight. I saw him. I was so ashamed, I told him right out, "I'm gonna make a man out of you or I'm gonna bust you up into little pieces trying." When he was fifteen he hit me in the face. He's big, you know. I haven't seen him in three years. Rotten kid! You work your heart out. . . . [Pause] All right, let's get on with it. (21)

This affects Juror Three and his attitude toward the situation. He becomes increasingly angry and hostile—even threatening to kill Juror Eight at one point, which only proves Juror Eight's point that the defendant may have threatened to kill his father in anger with no intention of doing so. 
Juror Three is so confident in his own understanding of the case that he is dismissive about viewing the evidence again, even though the defendant will likely be put to death if found guilty. When Juror Eight asks to view the murder weapon again, Juror Three says, "We all know what it looks like. I don't see why we have to look at it again. [To Four] What do you think?" (22). When Four agrees that seeing the knife is okay, Juror Three changes his attitude and says it is fine with him. This shows his initial bias—he is not even willing to initially consider that he could be wrong.
One thing that interferes with Juror Three's own sense of certainty is when others abandon the case. In act 3, he argues that it is possible the witness is far-sighted and saw the murder clearly despite her glasses; everyone else is saying she is unreliable because of her glasses. He says, "How do you know what she saw? Maybe she's far-sighted. . . [Looks around. No one answers. Loudly.] How does he know all these things? [There is silence]" (62). 
As the room slowly turns against him (the other jurors are unwilling to validate his opinion), Juror Three loses his firm stance. He votes not guilty in the conclusion. Rose writes that his "face contorts and he begins to pound on the table with his fist. He seems about to cry" (63). He changes his decision, so everyone is able to leave and the defendant is not guilty. 
It is clear that Juror Three is motivated most by his own prejudices against his sons. The only thing that interferes with that certainty is the negative opinion of others, as demonstrated by his reaction before he changes his vote.
Juror Eight is the man who first says it is possible the defendant is not guilty. Nothing changes his tune throughout the play because he is looking at the evidence, rather than his own prejudices. He also considers things from other perspectives. For example, Juror Eight has a knife much like the defendants. When his argument that someone could have used a similar knife is challenged, he responds:

Eight: I got it last night in a little junk shop around the corner from the boy's house. It cost two dollars.
Three: Now listen to me! You pulled a real smart trick here, but you proved absolutely zero. Maybe there are ten knives like that, so what?
Eight: Maybe there are.
Three: The boy lied and you know it.
Eight: And maybe he didn't lie. Maybe he did lose the knife and maybe he did go to the movies. Maybe the reason the cashier didn't see him was because he sneaked into the movies, and maybe he was ashamed to say so. [Looks around] Is there anybody here who didn't sneak into the movies once or twice when they were young? (24).

It is clear that the only thing that would sway Juror Eight is fact. Because he is willing to entertain other scenarios and is not disposed to automatically believe the prosecution's case, he remains unswayed. Instead, he creates reasonable doubt for others. He also has a tendency to challenge their beliefs by asking them questions rather than feeding them information. This indicates that he is skilled with people and is able to integrate the ideas of others into his own perceptions of things. 
Even though he argues on behalf of the boy, Juror Eight is not saying he is innocent. When Juror Four insists that Juror Eight does not believe the boy guilty, Juror Eight simply responds, "I have a doubt in my mind" (25). Unlike the others on the jury, Juror Eight is unwilling to come to a quick decision simply to escape a hot room without air-conditioning. 
Juror Eight is also willing to consider that he himself could be wrong. Even though he is doubtful as to the boy's guilt, he says:

Eight [standing]: I've got a proposition to make. [Five stands and puts his hands on the back of his chair. Several jurors glare at him. He sinks his head down a bit, then sits down.] I want to call for a vote. I want you eleven men to vote by secret ballot. I'll abstain. If there are eleven votes for guilty, I won't stand alone. We'll take in a guilty verdict right now. (26)

Of course, the ballot shows that someone else now has doubt about the case. Juror Eight's willingness to return a verdict of guilty shows in some ways how fair he is. He has presented his evidence; he does not believe the boy is necessarily the killer. However, he is willing to admit that he might be wrong. He is willing to admit that if his argument has not swayed a single person, it might not be the right argument. 
Juror Eight is also shown to care about the facts of the case more than his own emotions. When Juror Three and Juror Eight argue, Juror Eight says, "I'm sorry for you. . . . You're a sadist. . . . You want to see this boy die because you personally want it—not because of the facts. [Spits out words.] You're a beast. You disgust me" (42-43). Here, Rose shows that Juror Eight is not arguing to save the defendant's life because he does not want the young man to die, he is doing it because the facts of the case just are not convincing enough.
Juror Eight is shown throughout the play to be rational, clever, and convincing. Rose shows him leading other characters to the conclusion that there may be a reasonable doubt as to whether the boy committed the murder. Not once in the play does Juror Eight shy away from the men who stand opposed to him. Rather, he coaxes them to take a second look at the evidence. 
Juror Ten believes the young man is guilty because of both the evidence and his own prejudice. He says, "Look at the kind of people they are—you know them" when discussing the incident with the other jurors as they first leave the courtroom to discuss the case (13). He does not have much regard for people like the defendant. He says, "A kid kills his father. Bing! Just like that. Well, it's the element. They let the kids run wild. Maybe it serves 'em right" (13).
Juror Ten's prejudices are strong and are not swayed by multiple people's changed votes, arguments, or the doubt that Juror Eight has cast on the witnesses' stories. Even in act 3, he says: 

Ten: I don't understand you people. How can you believe this kid is innocent? Look, you know how those people lie. l don't have to tell you. They don't know what the truth is. And lemme tell you, they— [Five gets up from table, turns his back to it, and goes to window.] —don't need any real big reason to kill someone either. You know, they get drunk, and bang, someone's lying in the gutter. Nobody's blaming them. That's how they are. You know what I mean? Violent! (59).

He does not stop even when every other juror in the room has turned their backs on him—until Juror Four says that he will split his skull if he does not stop.
However, Juror Ten is swayed and does end up willingly changing his vote right near the end. After Juror Eight and the others discuss one of the witness's problems with her vision, Juror Ten changes his vote. He says, "I will always wonder. But there is a reasonable doubt" (62). This quote shows that he still does not fully believe the young man is innocent. However, he does think, finally, that some of the arguments are strong enough to make him unsure as to whether he should vote for guilt, which will lead to a death penalty. 
Jurors Three and Ten have strong opinions that do not change easily throughout the play. It can be argued that Juror Three does not really change at all—he just gives into the pressure of the other jurors rather than examining the evidence and admitting that doubt exists. Both Juror Ten and Juror Three rely on their own prejudices rather than the facts in front of them. Juror Eight, in contrast, is a man who reveres facts and values the concept of reasonable doubt—enough so that he insists on arguing even when 11 other men stand against him and want to render a guilty verdict immediately.