Both shows will end production at the end of the year after 1,700 episodes of "Attack of the Show" and 1,300 episodes of "X-Play."
"Attack of the Show!," perhaps best known for launching the career of former host Olivia Munn, has focused since its 2005 debut on technology, games, pop culture, movies and videos. Candace Bailey and Sara Underwood now host.
The gaming-obsessed "X-Play" debuted in 2003 on G4's previous incarnation, TechTV. It is now hosted by Morgan Webb and Blair Herter.
G4 said several guest co-hosts -- including John Barrowman, Michael Ian Black, Josh Myers, Paul Scheer, Rob Huebel and Horatio Sanz -- would appear in the last two months of episodes for both shows.
"'Attack of the Show!' and "X-Play" have been important for G4, and we want to acknowledge the creative people who have helped inspire and showcase the phenomenon of gamer culture,” G4 Media general manager Adam Stotsky said. “With more than 3,000 episodes aired between them, we have more than enough great material to honor these innovators and their amazing contributions as we bring both shows to a close.”