This is one of the very best! 

Quietwalk's revolutionary underlayment smooths out minor sub floor imperfections while quieting impact sound and floor to ceiling noise. In addition to its sound deadening benefits, the absorbing action of the synthetic fibers together with the attached vapor barrier provides superior moisture protection that is backed by a Limited Lifetime warranty. Another benefit is the increase in R-value to help keep floors warm in the winter, and cool in the summer. 

• Premium Underlayment for floating wood and laminate flooring
• Certified 92% recycled content
• Qualifies for LEED Credits: MR 4.1 and 4.2
• EPA-registered anti-microbial agent and high-temperature manufacture inhibit bacterial, fungal & dust mite growth.
• Adds R-value to chilly floors
• No detectable formaldehyde emissions.