The best arguments again NDEs based on testimony... NDEs tend to be varied - there are accounts of people having seen hell and heaven. An OBE is one category of NDE that I find very interesting. Imagine what it'd be like to see yourself doing stuff, well, actually just lying on an operation table. That would really rearrange one's beliefs in intersting ways.
As for a counterargument - the phenomenon isn't universally reported and hence, to that extent, dubious. The evidence itself is rather suspect - biased research is almost always a feature. Then of course is the issue of bad science - doctors, neuroscientists, quote unquote, aren't really physicists you know - their grasp of what science actually is wanting in many critical respects.