AKG is a specialized headphone brand. Their over-the-ear, full range, headphones are excellent. They may be a little more expensive than Koss or Sony at a given sound quality, but they have excellent sound quality and are good for programs hear or most music...
Koss is a specialty brand that offers a variety of quality headphones. Any decent Koss headphones that have full range (near 20-20Khz range), full coverage over the ear, will work well for the programs on this site and others like it.
Sony has a wide range of headphones from basic earbuds to high-end studio headphones. Their general full range, over-the-ear headphones are great for content like on this site. These will usually have buzzwords like ‘studio’ or ‘digital.’ ...
Sennheiser makes a wide range of headphones, from everyday headphones to supreme quality for audiophiles. Any of their headphones that cover the full ear should be good. Be careful about the ‘open/closed’ choice. I prefer ‘closed’ because...