This is a difficult question that isn't easily answered. The truth on this is that being from Egypt doesn't make the sheets any better than any other type of sheets on the market.
So, why are Egyptian cotton sheets special? Well, some Egyptian cotton sheets are better than others and it's those that are the best that have caused Egyptian cotton sheets to have the reputation for the luxury that they do. Those sheets are made from ELS cotton, which is also known as “extra long staple” cotton. The fibers of ELS cotton are longer than regular cotton, which means that anything made from them is less likely to pill or wear very much over time.
Egyptian cotton that is grown in the Nile River basin is the highest quality cotton available anywhere on the planet. It is the sheets that are made from the cotton grown there that are the highest quality that you can get. The climate is special and that makes the cotton grown there grow differently than it does anywhere else, even though it's the same species of cotton.
When you're looking for Egyptian cotton sheets and you want the best quality, make sure what you're looking at is “extra long staple” cotton. That's what makes the sheets the best, not the fact that the cotton comes from Egypt in general. luxuryofthepharaohs.com has some of the best low, mid, and high end brands.