There is no such fabric that could be called the most comfortable for everyday use. It would depend on factors both internal and external like
1. The Climate: Weather conditions can greatly influence our choice of fabric. Cotton is best suited for a hot and humid climate. This is because cotton fabric can absorb sweat faster and helps evaporate it. This is what produces the cool sensation on your body.
Linen is really a good fabric to use during summers. It is lightweight, it allows better air flow. The structure of the fabric is such that the fabric doesn’t stick to the body and allows proper airflow during the hot humid days. Another fabric of choice is Rayon made by blending cotton, natural fibre. This makes its structure light and non-sticky to the body. It also allows the passage of the air making the body cool in summer days.
In a similar manner, woolen clothes are preferred for cooler climates since it does not allow the cold breeze to penetrate keeping the body warm and hot. In a colder environment, you could also opt for silk or terrycot which provides warmth. Extreme cold can be dealt with aminal fabrics like chasmina, angora etc. But for the year round, one could stick to cotton, rayon, linen etc which are really comfortable.
2. Personal preferences: Some people might feel comfortable wearing cotton, but some of us could also be allergic to it. Some of the people like wearing jari sarees but some gets blisters draping them.