While teaching apologetics at Faith Bible Seminary I mentioned that there are a few scholars and some internet non-scholars who maintain that Jesus never existed. Two books that decisively refute this idea are: The Jesus Legend: A Case for the Historical Reliability of the Synoptic Jesus Tradition, by Paul Rhodes Eddy and Gregory A. Boyd; and The Resurrection of the Son of God, by N.T. Wright (especially chapter two).
Eddy and Boyd write: "Much of the fuel for the legendary-Jesus thesis is drawn from anachronistic approaches to the early Jesus tradition, approaches that are tied to a modern, literary paradigm. Our contention is that when the early Jesus tradition is assessed from an orally oriented perspective - and in concert with an appropriate historical methodology - the legendary-Jesus thesis becomes difficult to maintain... We will provide an overview of eight major lines of argumentation that are typically proffered by defenders of the legendary-Jesus thesis." (15)
Eddy and Boyd are so thorough that their book becomes the text that must be looked at if one thinks Jesus didn't exist as a historical person.