Chris Hallquist's book, UFOs, Ghosts, and a Rising God, is a nice compendium of skeptical responses to Christian historical apologetics. One of its central general theses is that if we were to use the methods people use today to discover the legitimacy of anything from UFO claims, to paranormal claims such as levitation, spoonbending or Mesmerism, to false prophets like Nostradamus, Jean Dixon, or Edgar Cayce, we would find the Christian claims severely wanting.
In his first chapter called "A Brief History of (de)Bunk(ing), Hallquist gives a number of accounts of debunked claims, but I notice that all of them involve some kind of deliberate fraud or other. He talks about the prophet Alexander, from ancient times, who was exposed as a fraud, and Mesmer, and the Fox sisters, etc. In the case of the Resurrection, however, Hallquist appeals to deliberate fraud on the part of the early Christians, at most, as a possibility. With respect to the premortem miracles of Jesus, Hallquist claims that Jesus was scientifically ignorant, and sincerely thought he was healing people, even though his healings were in fact psychosomatic. (Can you cure blindness psychosomatically?)
There are two reasons, I think, why skeptics in general have mostly avoided deliberate fraud hypotheses. The first has to do with the moral character of Christ. It is not that the moral character of Christ is above possible criticism, and there are "hard sayings" which on the face of things can be objected to on moral grounds, and yet there seems to be a fundamental difference in character between Christ and the leaders of the Heaven's Gate community, Warren Jeffs, David Koresh, Jim Jones, and even Joseph Smith. I think Christ's parable of the Good Samaritan is the most brilliant piece of moral philosophy in the history of the world, but then I suppose that reflects my Christian bias.
The second is that not only Jesus, but other founding figures of the Christian church. particularly James, are known to have been martyred. We should expect people involved in a hoax or fraud to head for the exits if the continuation of the fraud were to be a threat to their own life.
The skeptical responses Hallquist does provide are, of course, hallucinations for the appearances, and he thinks the empty tomb stories were probably legendary. Indeed, his general strategy is remarkably similar to the one mapped out by Keith Parsons in his 1998 debate with William Lane Craig. The audio is linked to here, and Jeff Lowder's summary is here. Parsons also brings up UFOs and alien abductions.
If the founding of Christianity could be dismissed as some kind of deliberate fraud, the skeptic's case would be a good deal easier than it is. Further, while we are farther removed from the events than we are from, say, the frauds of, say, Peter Popoff/Steve Martin (see the movie Leap of Faith), the impact of these events on history is undeniable.
In the case of Christianity, we seem to have several people who put their own lives at severe risk and even who were in fact martyred, as a result of their refusal to renounce their belief that they had seen the resurrected Jesus. Now, as Jenkin was quoted as pointing out on p.32 of the McGrews' essay on the argument from miracles, while the mere fact of martyrdoms doesn't prove anything more than sincere belief, the martyrdom of witnesses is another matter entirely.