Old cotton terry cloth towels that are soft and thirsty are undoubtedly the best. They are at their best just before they start to fray around the edges.

Avoid using fabric softener and drier sheets. It is counter intuitive but softener gets into the fibers and can, over time and many washes, make a towel much less absorbent.

And back off on laundry detergent also. Most people think the more detergent you use the 'cleaner' the clothes but the opposite is the fact. use too much detergent and it doesn't get rinsed out. Which makes clothes stiff and scratchy and uncomfortable. Which causes people to use softener. Which can attract and hold dirt. An endless cycle.