Live Action Great Teacher Onizuka 2012 - English Sub Episode 1:
Ex bike gang leader Onizuka becomes a school teacher .. his straight ahead attitude make him an odd, but successfull teacher. EDIT - 02/07/17 - Looks like no English sub exisits at the moment for the 2012 TV series, will update when one bcomes available. -
There's another earlier live action series from the late 1990's, as well as a few earlier live action movies .. these characters are based the early animated series and manga.
Great Teacher Onizuka  [ENG SUB] [JAP] [TV-Special]
EDIT - dead link renewed for the GTO movie.