Mark-Paul Gosselaar had trouble saying goodbye to his character, prankster Zack Morris, and reprised his role for the college years spin-off and the series' made-for-TV movies. Gosselaar scored a lead role in 1998's "Dead Man on Campus" but failed to gain momentum in Hollywood. After the short-lived TV series, "Hyperion Bay," Gosselaar finally moved beyond his Zack Morris typecast when he took on the role of Detective John Clark on "NYPD Blue" from 2001 to 2005. His most recent show, "John From Cincinnati," was canceled, but appeared on TNT's "Raising the Bar" in 2008.
(NBCU Photo Bank, via AP/Getty Images)