Early roles include Noah Allen from Nickelodeon's the Mystery Files of Shelby Woo. He had a small part in the movie Léon, and starred in an episode of Law & Order. He also had a small part as the nerdy AV geek in that movie about the cheerleaders that rob banks "Sugar & Spice"
Busch appeared on Fox Network's brief series The Jury in Summer 2004, which ran for ten episodes, and has recently been seen in a character role on House. Most recently, he portrayed the Orthodox Jewish rap artist, Sholom Glickstein, in the Paul Weitz film, "American Dreamz". He had a recurring role in the new Kelsey Grammer situation comedy, Back to You. Recently he made a guest appearance on Terminator: The Sarah Connor Chronicles.
Busch is currently (2008) in a relationship with former Buffy the Vampire Slayer co-star Amber Benson. In the series, it was Busch's character Warren Mears that killed Benson's character Tara Maclay.
Outside of acting, Busch is the front man of a folk/indie band called Common Rotation. His dream role would be to portray longtime rocker Huey Lewis in a biopic of Huey Lewis and the News.