McLain provides voices for many characters in several video games from
Valve. Among them are
GLaDOS, the primary antagonist of the
Portal video game series (for which she won an
AIAS Interactive Achievement Award for Outstanding Achievement in Character Performance), the announcer in
Team Fortress 2; and the voice of the
Combine Overwatch for the
Half-Life series. McLain sang "
Still Alive" and "
Want You Gone", the ending credits songs to
Portal and
Portal 2, respectively, both of which were written by
Jonathan Coulton. She also sang "
Cara Mia Addio" at the end of
Portal 2. In December 2011, McLain won the
Spike Video Game Award in the category "Best Performance by a Human Female" for her voice acting as
GLaDOS in
Portal 2. In 2013, she lent her public support to gathering donations for the
Kickstarter-funded LGBT gaming convention
GaymerX. She later was a special guest at the convention in August 2013. In 2014, she portrayed Fairy Godmother in the online video series
[Wish It Inc.]. In 2015, she portrayed Lisa Clarke in the gay independent film,
Winning Dad. This film was also promoted on McLain's YouTube channel. McLain has played roles in many radio dramas on the radio program
Imagination Theatre. In 2021, McLain provided the voice of GLaDOS non-canonically, singing a verse in
The Chalkeaters’ song "
Count to Three" as a cameo. Also in 2021, McLain performed the role of Thelma (or Mama) in a livestreamed version of the play
'night, Mother co-starring Sheila Houlahan on the online platform
Twitch with the story adapted by McLain within the context of the
COVID-19 pandemic. The filmed online play, directed by McLain's husband
John Patrick Lowrie, is performed through an online face-to-face chat with the screen split between McLain's and Houlahan's screens, occasionally interrupted by cuts to pre-filmed footage relevant to the story. In 2022, McLain provided the voice of GLaDOS for the
GEICO Insurance ad. == Personal life ==