Amy Poehler, George R.R. Martin and Seth Meyers Amy Poehler, George R.R. Martin and Seth Meyers

This week, Ellen DeGeneres launched her own video channel, called EllenTube, and Daniel Radcliffe showed off his (impressive!) rapping skills on The Tonight ShowAmy Poehler and Seth Meyers decided to find out just how well George R.R. Martin knows Game of Thrones, and the cast ofDancing With the Stars got scared out of their minds while prepping for the Halloween episode. Also, a woman in New York filmed herself walking around the city to demonstrate how often women get harassed on the street. Check out those clips and more in our weekly roundup of the best online videos:

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NYC Street Harassment: Don't believe that street harassment is real? Check out this video, in which New York resident Shoshana Roberts gets catcalled more than 100 times over 10 hours spent walking the city streets — in jeans and a T-shirt.

Daniel Radcliffe raps "Alphabet Aerobics": Who knew Harry Potter could rap? During a visit to The Tonight Show this week, Radcliffe demonstrated his hidden talent by performing Blackalicious' "Alphabet Aerobics" (with a little help from Jimmy Fallon).

Dancing With the Stars spooky scare montage: In between fits of laughter, try and sympathize with the stars and pros of Season 19 as they get startled again and again by pro Sasha Farber (who's wearing a terrifying mask).

Game of Thrones trivia with Amy Poehler: How well can George R.R. Martin identify quotes from his Game of Thrones characters? Find out in this Late Nighttrivia game with Seth Meyers and Amy Poehler:

T-Pain sings live: Rapper T-Pain is known for his liberal use of AutoTune, but this NPR video of him singing "Buy U a Drank" without any technical assistant makes the case that he should start relying more on his own vocal abilities.

EllenTube: Ellen DeGeneres has launched her own online video channel, EllenTube (get it?), which will showcase "hilarious and family-friendly" clips. In this video, Lena Dunham and Melissa McCarthy play "Heads Up!"

OK Go's "I Won't Let You Down": Music-video masterminds OK Go have done it again. Here's the characteristically elaborate video for their new song, "I Won't Let You Down."