Because scorn seems to be the most common response to mythicism from some academics, I try to note those rare occasions when this idea non grata is actually engaged with some modicum of seriousness and professional respect by a scholar who seeks to refute it. My first encounter with this kind of level-headed approach to refuting mythicism was a debate between Greg Boyd and Robert Price some years ago. Boyd has since co-authored two books with Paul Eddy — The Jesus Legend and Lord or Legend (the latter is a popular condensation of the longer and more-annotated former), which both lay out a case against mythicism. Theirs is an attempt at a rational and systematic approach to the topic. It is clear from the onset that Boyd is a reasonable man who's willing to at least entertain the idea for long enough to construct an argument against it based on his understanding of what he perceives to be the unlikeliness of a Jesus "legend" having taken hold like it did. It is an honest attempt to project the implications of the theory onto a working model. I think his conclusions are wrong, of course, but Boyd's stance is a huge improvement from the simple-minded dismissiveness of most of the current vocal opponents of the theory. As an example of what I mean by Boyd's reasonableness, consider the fact that during a Q&A session at the end of the same debate Boyd agreed with Price that none (i.e. "zero") of the so-called "fulfilled O.T. prophecies" held by many evangelicals to foretell Jesus' coming are at all relevant or even refer to Jesus; they are all taken out of context and are useless as evidence. Boyd reasons (correctly) that such a prophetic reading of these passages would require the forcing of a context onto Hebrew stories that had not been there before these gospel authors began to scour the psalms and suchlike in search of scriptural muscle to reinforce their developing tradition. Boyd does not accept these as "prophecies" of Jesus, and this shows me that he is no unthinking lemming intent on defending an indefensible party line. He's trying to be honest when faced with evidence. His arguments, however, in the end turn out to be as full of circular reasoning (such as when he ascribes "eyewitness" status to a gospel ), unconscious equivocation (when he misrepresents "ἀδελφὸν τοῦ Κυρίου" as though it read "ἀδελφὸν τοῦ Ιησοῦ"), special pleading (when he views the will to believe as a valid epistemological tool), that is, all the common apologist fallacies, as some of his less-well-mannered peers' are. But at least he is not a dick about it. He's not malicious at all. A gentleman, he is always courteous.
The main thrust of Boyd and Eddy's refutations revolves around the Jewish context of the developing myth and the reasons for thinking that mythicism does not fit this context. I once considered it a good counter argument, but I no longer do. I wrote a more a detailed post about it, as I regard Boyd and Eddy's books to be some of the better historicist books out there currently.