This reply isn't helpful, and I'm sure there's a 'best' rope out there but if there's anything I've learning about hanging, it's if there's a will there's a way. I'm guilty for reading a lot of news articles about suicides and the list of ligature types is endless in these successful attempts. Climbing rope, cable ties, elastic bands, bed sheets, belts, scarfs, electrical cables, towels, T-shirts, the list goes on.. hanging is one of the most accessible and common methods because of that. I'm sure some are softer or more comfortable than others, but if the person is determined enough it doesn't matter what you use