It was during this period that he struck up friendships with future MST3K stalwarts Michael J. Nelson, Trace Beaulieu, Bridget Jones and others, as well as Lizz Winstead, later co-creator of The Daily Show on the Comedy Central network.

Conniff was appearing in a North Dakota venue when he was informed by MST3K head writer Nelson that he had been selected to replace one of the show's original cast members, J. Elvis Weinstein.

[2] He starred in the 2010 computer game Darkstar: The Interactive Movie as both Navigator Alan Burk and the voice of the robot SIMON (Semi Intelligent Motorized Observation Network).

[6] On October 30, 2007, original MST3K host Joel Hodgson announced he was starting a new show with the same "riffing on bad movies" premise as MST3K called Cinematic Titanic, together with former MST3K cast and crew members Conniff, Beaulieu, Weinstein, and Mary Jo Pehl.

[8] Since 2015, Conniff has joined his former MST3K co-star Trace Beaulieu ("Dr. Clayton Forrester") and gone on tour as "The Mads Are Back",[9] riffing older B-movies in front of live audiences.