Guest announcer Kelsey Grammer, the Backstreet Boys perform, plus Olympic gold medalist Apolo Ohno.

Guest announcer Kelly Ripa plus singer Ray Parker Jr. and journalist Meredith Vieira.

Guest announcer Reba plus singer OMI, and actors Jesse Tyler Ferguson and Jane Krakowski.

Guest announcer Jack Black plus Olympic Gold medalist Apolo Ohno, and journalists Matt Lauer and Savannah Guthrie.

Guest announcer Shaq joins Neil for an evening full of fun, games and housewives, with special guests Gloria Estefan, Zachary Levi and Blue Man Group.

Tyler Perry is this week's celebrity guest announcer.

Emmy Award winner Alec Baldwin serves as this week's celebrity guest announcer.

Reese Witherspoon serves as the celebrity guest announcer during the series premiere of this variety show hosted by Neil Patrick Harris, which features A-list stars, performances, stunts, comedy skits, mini game shows, audience giveaways and hidden camera pranks. Based on the British series "Ant & Dec's Saturday Night Takeaway."