The Greatest Prophet in Christianity is and has always been St. John the Baptist.
St. Matthew 11: 11-15 Verily I say unto you, Among them that are born
of women there hath not risen a greater than John the Baptist:
notwithstanding he that is least in the kingdom of heaven is greater
than he. And from the days of John the Baptist until now the kingdom
of heaven suffereth violence, and the violent take it by force. For
all the prophets and the law prophesied until John. And if ye will
receive it, this is Elias, which was for to come. He that hath ears to
hear, let him hear.
Jesus Christ is not the greatest prophet, because prophets point to The Way(Jn5:38-40), their purpose is to call people back to The Way. But Jesus himself is The Way(Jn14:6), and so cannot be a prophet properly speaking. He is the liaison between the supernatural and the natural leading to the divine and so to salvation. In effect being both God and man to fulfill this role, but that's another story, or is it?
We read in the Gospel of St. Matthew 16:13-18 :
13 When Jesus came into the coasts of Caesarea Philippi, he asked his
disciples, saying, Whom do men say that I the Son of man am? 14 And
they said, Some say that thou art John the Baptist: some, Elias; and
others, Jeremias, or one of the prophets.
From verses 13-14 we can see that the masses have various differing
ideas of who Christ is, some believe he is a prophet. Also the mention
of St.John the Baptist in this enumeration shows that his personnage
was of significance. The rest is self-evident, St. Peter declares that
Jesus is Christ Son of God infallibly(v.17) which means the previous
titles were not only fallible but also false. He is not a pointer, he
is the point. The power is not outside of him, the power is him.
15 He saith unto them, But whom say ye that I am? 16 And Simon Peter
answered and said, Thou art the Christ, the Son of the living God.
17 And Jesus answered and said unto him, Blessed art thou, Simon
Barjona: for flesh and blood hath not revealed it unto thee, but my
Father which is in heaven. 18 And I say also unto thee, That thou art
Peter, and upon this rock I will build my church; and the gates of
hell shall not prevail against it.
To amplify this answer let us take a look at the parallels between Jesus the Christ and St. John the Baptist, and they have their place. These will be bullet points, you are welcome to look up the references and overtime I might integrate them into the list.

- Both men were prophesied by the prophet Malachi
- Both men had births which an angel foretold
- They had a fusional relationship together before birth(more on this below)
- Both men preached about repentance and the Kingdom of Heaven
- Both men criticized the religious leaders of the day
- Both men were accused of operating by demonic influence/power
- Both men had devout disciples
- Both men were persecuted because of their preaching
- Both men were arrested for ludicrous reasons.
- Both men were killed because of the rulers sinning by omission
- Both men had people who came and asked for their dead bodies
I will end this answer by expounding a bit on this fusional relationship they had before birth, this is very important to understand the holiness of St. John the Baptist.
King David is a type of St. John the Baptist, and the latter one is superior.
In the Old Testament the Ark of the Covenant was the seat of God on Earth, his presence was seated on this throne and reassured. The Israelites even took it with them in war to bless the warriors before battle.
One day in a festive setting, King David stripped himself almost entierly naked and danced in the presence of the Ark in honor of God(2 Samuel 6:9-15). This same pattern is repeated in the New Testament when Mary, who holds God inside of her and is therefore the Living Ark of the Covenant, makes St. John the Baptist jump with joy being animated by God's Holy Spirit inside of the womb of his mother Elizabeth at the mere sound of here salutation(St. Luke 1:41-47). King David was one of the holiest men in the Old Testament, so much so that Christ is called Son of David. Therefore seeing this New Testament overdose of grace as it were, since David danced when he was aged while St. John danced when he wasn't even born yet, it can be taken to be indicative of St. John the Baptist's exceptional spiritual maturity. This is even more obvious when we take into consideration the "three months" in 2 Samuel 6:11 and St. Luke 1:56, the number 3 of course having its own deep theological background.
To put emphasis on the "majority view" part of this question, I first
remind you all that Catholics make up 52% of Christians(majority), add
to that the Orthodox who make up around 20% of Christians and we're at
70%, stronger majority. According to both of the Churches, St. John
the Baptist is the Greatest Prophet.
"O glorious St. John the Baptist, Greatest prophet among those born of
woman"(Novena of St. John the Baptist)
"He that was greater than all who are born of women, the Prophet who
received God's testimony that he surpassed all the Prophets, was born
of the aged and barren Elizabeth"(Saint John the Baptist Orthodox
Church Western Rite mission of the Antiochian Orthodox Christian
Archdiocese of North America)
"They also embrace a tradition that, following his death, John
descended into Hell and there once more preached that Jesus the
Messiah was coming."(Orthodox Wiki)
However this does not make him the Greatest Human Being in the eyes of God Almighty, there is one who is even holier. You see, this time again we will exclude Jesus Christ, for it is true that he is a human being but he is not a human person. He is a divine person. The change in vocabulary is too subtle for most and so if I answered Jesus you would feel cheated. Instead I will answer by indexing the Greatest Human Being and Human Person, not St. John the Baptist for he is in second place, but instead and to the dismay of many, a woman, the Blessed Virgin Mary is the number one.

- Mary is Mother of God, also known as Theotokos meaning God-bearer
- Mary is Ever Queen of Heaven
- Mary is the new Ark of the Covenant
- Mary is the new Eve
- Mary is the Mother of the Church
- Mary is the Immaculate Conception(Jesus is the Virginal Conception)
I already expounded on her role as Ark of the Covenant, although more can be said, but for the purposes of this format I will not do so. The Immaculate Conception is also quite significant, as it teaches that she is without sin just like Jesus Christ, and therefore disqualifies everyone except Jesus Christ. She never sinned nor was she born in sin, this does not mean she wasn't saved or didn't need Jesus. The biblical explanation would be too long to present here, but Catholic Answers has some interesting material to present. I also recommend Dr. Scott Hahn.
Emphasis added once more :
"971 "All generations will call me blessed": "The Church's devotion to
the Blessed Virgin is intrinsic to Christian worship."515 The Church
rightly honors "the Blessed Virgin with special devotion. From the
most ancient times the Blessed Virgin has been honored with the title
of 'Mother of God,' to whose protection the faithful fly in all their
dangers and needs. . . . This very special devotion . . . differs
essentially from the adoration which is given to the incarnate Word
and equally to the Father and the Holy Spirit, and greatly fosters
this adoration."516 The liturgical feasts dedicated to the Mother of
God and Marian prayer, such as the rosary, an "epitome of the whole
Gospel," express this devotion to the Virgin Mary.517" (Cathechism of
the Catholic Church)
"The Orthodox Church honors and venerates the Virgin Mary as "more
honourable than the Cherubim and more glorious without compare than
the Seraphim …" Her name is mentioned in every service, and her
intercession before the throne of God is asked. She is given the title
of "Theotokos" (Greek for "Birth-giver-of-God), as well as "Mother of
God". She has a definite role in Orthodox Christianity, and can in no
way be considered an instrument which, once used, was laid aside and
forgotten."(Orthodox Christianity, Archbishop Dmitri)
Roman Catholic Mariology contends that a veneration (hyperdulia)
should be given to Mary that is higher than the dulia given to the
other saints. Worship (latria) is properly given only to God. While
Anglicans can agree that God alone is to be worshipped, many do not
agree that Mary should receive a degree of veneration above the other
saints. Some Anglicans agree with the Eastern Orthodox that Mary is
simply the greatest of all the Saints, and that she should be
venerated as such (that is, dulia).(Anglican Marian Theology,
Wikipedia)
Everything I have presented here, from St. John the Baptist to the Blessed Virgin, is the Majority View in Christianity. Catholics make up 52% of Christians, add to that the Orthodox and a few Protestants and you're at over 70% of Christians agreeing with me. Although the Immaculate Conception is exclusively a Catholic thing, but the Orthodox sometimes have a semblance of this. Either way it is the Majority View, we cannot satisfy everyone can we.
IN SUMMATION this is why St. John the Baptist is and will always be the Greatest Prophet in Christianity, and the Blessed Virgin Mary is undethronable Most Holy Human Being and Person that has ever walked this Earth.