What was the first Hip Hop song to reach the Billboard Top 40?
Answer: Rapper's Delight by the Sugar Hill Gang
Hip hop’s roots as a musical phenomenon are subject to debate, but its roots as a commercial phenomenon are much clearer. They trace back directly to January 5, 1980, when the song “Rapper’s Delight” became the first hip hop single ever to reach the Billboard top 40. - History
This one is awesome and not too much needs to be said about it. Rather than ramble on, just take a minute to enjoy the video instead.