The four most important mass-media are the radio,the newspaper,the television and the web.
The radio was the most important mass media in the majority of 20th century but after 10th May 1947,that says the famous song "video killed the radio star"," video killed the radio star, pictures came and broke your heart".The newspaper is the first means of communication and now is important but less than after.
In my opinion,the web is the most popular,important and useful mass-media because it contains in itself all the functions of the other three.On the web you can do a lot of things,read newspaper,compare news from different web site, chat with your friends,meet and know other person,send or receive email,video call persons distant to you,see films,listen music,have bent millions information and you can even pay a bill!
The radio is an important means of communication but a news heard on the radio is different to a news heard on television or the web because you can see videos,pictures and heard sounds.
I think that the radio,the television and news papera are much popular and important but for the modern society the web is the most popular,important,useful,fast and practical mass-media.