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Best Guest List: Katy Perry's "E.T." featuring Kanye vs. Lady Gaga's "Telephone" featuring Beyonce
Special guest verses are nothing new in top 40 hits, but these two jams have some pretty big names to take them over the top. Beyonce's willingness to take part in Gaga's caper for the "Telephone" video certainly makes for a superhero-sized rivalry with the gusto of Kanye West's contributions to otherworldly "E.T."
- Katie Hasty