What are some of the best camcorders for audio quality for singing and playing guitar?

what you really need is to mic your guitar and yourself separately, then properly mix the two signals together so that it sounds right.

Once that is done, lip sync the song while recording yourself. If this is too much, then all DV camcorders record sound great. make sure the camcorder isn't too close to you so that the instrument doens't over whelm the recording...