Abdullah ibn Amr narrated:
"Allah's Messenger (s.a.a.w.) neither spoke in an insulting manner nor did he ever speak evil intentionally. He used to say, 'The most beloved to me among you is the one who has the best character and manners.'" (Narrated by Al-Bukhari) 

AbuHurayrah narrated that the Prophet (s.a.a.w.) said:
"The most Perfect believer in respect of faith is he who is best of them in manners." (Narrated by Abu-Dawood)

Qatadah ibn Malik narrated that Zayd ibn Ilaqah related on the authority of his uncle, Qatadah ibn Malik, that the Prophet (s.a.a.w.) would supplicate:
"O Allah, I seek Your protection against undesirable manners, acts, and desires." (Transmitted by Al-Tirmithi.)

Anas ibn Malik narrated:
"I was walking with the messenger of Allah (s.a.a.w.) and he was wearing a mantle of Najran with a thick border. A Bedouin met him and pulled the mantle so violently that I saw this violent pulling had left marks from its border on the skin of the neck of the Messenger of Allah (s.a.a.w.). And he (the Bedouin) said: Muhammad!, command that I should be given out of the wealth of Allah which is at your disposal. The Messenger of Allah (s.a.a.w.) turned to him and smiled, and then he ordered for him a provision." 

He also narrated:
"Eighty men from the men of Makkah descended upon the Messenger of Allah (s.a.a.w.) from the mountain of Al-Taneem, in [full] armor, with the intent of doing battle with him. He (Muhammad, s.a.a.w.) captured them peaceably and then did not kill them" (Narrated by Muslim) 

A pagan by the name of Zaid ibn Sa'ana came to the Messenger of Allah (s.a.a.w.) in order to collect a debt. When he drew near Muhammad (s.a.a.w.) he wrenched him by his clothes violently, exposing his shoulder, and spoke rudely at him. Finally, he said: "You sons of AbdulMuttalib are all a procrastinating lot." Immediately, Umar ibn Al-Khattab leapt at him chastising and rebuking him harshly, all the while the Messenger of Allah (s.a.a.w.) looked on smiling. Then the Prophet (s.a.a.w.) said to Umar: "He and I were in need of other than this O Umar; You should have commanded me to excel in my repayment, and have commanded him to excel in his request for repayment." He (Muhammad, s.a.a.w.) said: "There [still] remains in his term three [days]" He (Muhammad, s.a.a.w.) then commanded Umar to see to his recompensation and to increase him twenty 'saa' (weights) as compensation for the terrorization he had endured (from Umar). This man later became a Muslim" (Narrated by Al-Bayhaqi, ibn Habban, and Al-Tabarani) 

Anas ibn Malik said:
"Allah's Messenger (s.a.a.w.) had the best disposition amongst people. He sent me (when I was a child) on an errand one day, and I said: By Allah, I would not go. I had, however, this idea in my mind that I would do as Allah's Apostle (s.a.a.w.) had commanded me to do. I went out until I happened to come across children who had been playing in the street. In the meanwhile, Allah's Messenger (s.a.a.w.) came there and he caught me by the back of my neck from behind me. As I looked towards him I found him smiling and he said: Unays, did you go where I told you to go? I said: Allah's Messenger, yes, I am going. Anas further said: I served him for nine years but I know not that he ever chastised me about a thing which I had done why I did that, or about a thing I had left as to why I had not done that." (Narrated by Muslim)

In another narration, he said:
"I served the Prophet (s.a.a.w.) at Madinah for ten years. I was a boy. Every work that I did was not according to the desire of my master, but he never said to me: Fie!, nor did he say to me: Why did you do this? or Why did you not do this?" (Narrated by Abu-Dawood)

Ibne Malik also said:
"No one was more beloved to us than the Messenger of Allah (s.a.a.w.), [however], if we saw him we would not stand up for him for we knew how much he disliked [for us to do so]. And on one occasion someone called to him saying: 'O best of mankind ...' He replied: 'That is Abraham, peace be upon him' " (Narrated by Muslim)

Adi ibn Hatim al-Ta'ee came to the Prophet Muhammad (s.a.a.w.) to ask about Islam, so Muhammad (s.a.a.w.) invited him to his home. When they sat down, a small girl brought a pillow to the Messenger of Allah (s.a.a.w.), however, he placed it between him and Adi and sat on the ground. Adi later said: "[When I saw that] I knew that he was not a king"

It was also narrated that Muhammad (s.a.a.w.) once said:

"I am but a servant, I eat as the servant eats, and I sit as the servant sits"

Muhammad (s.a.a.w.) would tie his own camel, feed his own animal, eat with the servants, knead dough with them, and carry his own groceries from the market.

Reference url: http://wings.buffalo.edu/sa/muslim/library/jesus-say/ch9.html