Christian apologists have long pointed out that when it comes to textual reliability, the NT is in a league of its own compared to all other ancient texts. According to NT manuscript expert Daniel Wallace, there are 1000x more copies of the NT than the average ancient Greek text. If we stacked the NT manuscripts on top of each other, they would reach more than a mile high. Not only are there more manuscripts for the NT than any other ancient text, but the gap between the original text and our first copies is smaller for the NT than other ancient texts. There are 3x as many NT manuscripts within 200 years of the original text than the average Greco-Roman text has in 2000 years.
Unfortunately, many of the statistics appearing in apologetics literature are outdated. Additional manuscripts of both the NT and other ancient texts continue to be discovered. Clay Jones wrote an article for the Christian Research Institute in 2012 providing the latest stats. The article was recently posted on the CRI website. Check it out and see how the NT compares to other ancient Greek texts.