In another YSACG video, Linkara becomes so frustrated with his cards that he starts quoting Tommy Wiseau, which results in him saying "Oh hai Liz. How's your sex life?". What makes this especially funny is how Liz chuckles a little at this at first...and then bursts out laughing when she realizes the implications.
Pretty much any time she finds a pun in something. Which she does. All the time.
The entirety of the "Mystery Date" YSACG episode, from Liz and Linkara dubbing all the player characters "Jackie Kennedy", to nicknaming the bowling guy "J. Edgar Hoover" (as well as all the FBI jokes that comes with), to the two occasionally going into stereotypically catty teenage girl banter, to pretty much every stab at 60's pop culture.
In her review of All Flesh Must Be Eaten, her attempting to think of a well known badass from a zombie flick that didn't die, before finally just giving up and settling with the obvious choice.