I don't know which is the most durable or whose word you would take for that but I do know that Simonis 860 is the cloth most used and that I"ve had it for years and is the only cloth I'd recommend.
I agree with JimS that Simonis 860 is the proffered cloth for players. Durability of cloth is usually based on the weight of the cloth 19oz. to 23oz., wether the cloth is backed or unbacked, percentage of wool to nylon blend, and if the cloth has been treated with teflon or some other stain guard. The question comes down to if you want a professional playing table with great speed or do you want a bar table that plays slower and can be cleaned easily? And no matter your choice make sure that the cloth does not get any direct sunlight. It will deter rate any billiard cloth.
For the durability I would have to suggest 3030 Tour Edition distributed by Championship (D&R), or Granito Basalt. Personally, I always kept fresh Simonis 860 on my table for every reason except durability. If you need a supplier let me know for anything billiard related... I will give you a pretty good deal on the material(s) and give you some pointers on covering. You can call me while you are doing it!
Simonis 860 is all we had on our 25 tables, but if not installed right,no cloth will last long,if its over streched under streched,not cleaned everyday,so on and so on. imo
Simonis 860 would be your best bet, I recovered a friends table with simonis 860 about 4 years ago and the cloth still pllays like it did when it was brand new. If you are looking to purchase please feel free to contact me and I'll see if I cant get you a great price on it and any other billiards related products.