Riff Regan Alyson Hannigan, Buffy The Vampire Slayer, TV, 1997-2003. Riff, the girl from Monterey, was Willow Rosenberg in the unaired pilot of Joss Whedon’s “high school as a horror movie” in small-town America. But Alyson won the series - all 144 episodes of it. Copyright © 2023 Crawley's Casting Calls. All Rights Reserved. Joomla! is Free Software released under the GNU General Public License.