That depends on the faith of who you ask.
If you ask a Muslim or a Jew, he was a great prophet sent by God to Announce the route to ultimate salvation. For Jews, the savior was to come. For Muslims, the salvation came in the teachings of the Prophet Muhammad.
If you ask an Eastern faith (Taoism, Buddhism, Hindu etc.) he was a great philosopher of the Middle East.
If you ask a secularist you will get "Who?"
If you ask a Christian: Jesus is the Christ, the savior promised in the Prophecies of the Old Testament. He died on a cross for the sins of humanity, was raised because he himself was without sin, ascended into heaven, and will come at a time we do not know to end the world, take all Christians to heaven, and leave all non-believers to destruction.
To answer the question of Jesus' identity, there are a number of possible perspectives. During his lifetime, some regarded Jesus as a militant savior from real and present political oppression. Others believed in him as more than met the eye: the Messiah, as prophesied throughout the Old Testament. Even to this day, the question of who exactly this remarkable Man/God was, or still is, remains undecided.
The most obvious current perspective is the New Testament, upon which Christianity is based. According to the New Testament, Jesus is identified as the Son of God and the "Son of Man." This means he was God who became human. The purpose of this incarnation was to establish a more attainable connection between God and his worshippers. He proved his humanity by dying on the cross and proved his divinity with the resurrection and ascension to heaven.
Other directions of thought consider as Jesus only a kind of prophet rather than as a deity. According to some, Jesus was a prophet of some note. These directions of thought do not acknowledge him as divine. Notably, religions such as Buddhism consider Jesus as a wise prophet with a connection to the divine, but not as a divinity himself.
When putting the question, "Who is Jesus?" some would claim to have a personal relationship with him. Others would acknowledge his ideas from a more distant perspective. Some may have negative perception of Jesus, while others may not know about him at all.