Everyone knows about Wikipedia the question is about to describe him like a normal person.We don't want to mug the stats and data, this answer wants experience,the thoughts and above all a layman explanation.So here it goes 

Mahendra Singh Dhoni: A calm, cool, intelligent, situational alert and organized person.He is an engineer who takes the last minute risk,an inventor who invents new ways to save the boundary and a cricketer by profession.
Whenever country needs him more than ever at most times. He delivers all the time , leading the country to victory. What People like about him

• He loves to repeat the history and he loves to chase the dreams of god and the people of India.

He has given India all the major ICC trophies

• He emerges from a low family background who earned  respect and gets a lot of love from people of India.

• He has played in his own style since the early days of his career  and that has never changed.

• One of the best finishers in cricket history who loves to quote "Nothing is Impossible".

• He shares the smile and brings the smile.

• Humility, spirit and confidence lives in his soul that describes him.

Remember these words of confidence during champions trophy

We are the number one team in the world, let's play like one.

• Consistency is the key of learning and criticism is good for his health.He blames himself when  team loses and if the team wins he gives the credit to his teammates.That defines him" One of the best leaders "of Indian Cricket team.

• His second love is to serve the country with full dedication.

• He loves what to do but he hates to study.

• He is also been nicknamed Witty Mahi or Funny Mahi.

Dhoni telling Sreesanth : 

"Sree come here, your GF is not there".

• He adores the pet and loves to ride the bike.

• He is known for building sporstman spirit in Cricket.

The excitment is watching him in last overs and he inspires me to become a better person.