Some popular free podcast downloads are "This American Life," "Radiolab" and "WTF with Marc Maron" as of 2015. Because of the rising popularity of podcasts, there are a wide variety that are available to download for free.
In the comedy world, "WTF with Marc Maron" is considered to be one of the best podcasts around. Marc Maron interviews an eclectic mix of subjects, ranging from Paul Thomas Anderson to President Barack Obama. "This American Life" is also an extremely popular and well-received podcast. As of 2015, it's the most popular podcast in the country. Some other very popular podcasts that can be downloaded for free are "How Did This Get Made?" "Kevin Pollack's Chat Show" and "Earwolf Presents."