In episode 15, Doug making Ask That Guy disappear after the latter had gone on a long rant about he couldn't be the figment of a good person's imagination because evil like him aways wins.
In episode 42, Doug rattles off three tongue twisters in rapid succession. We probably don't want to know how many takes that required.
Ask That Guy With The Glasses gets one during Episode 17. He opens the video answering a question with a long, drawn out, irrelevant reply. Then, he apologizes for wasting everyone's time, and provides a link to "The Greatest Video Ever" to make up for it. Its a Rick Roll. The next question? "How do I spot a Rick Roll?" His answer is an evil and a simple "You can't."
When Ask That Guy gets asked to assist in a suicide, he draws a gun, walks out the front door.. Basically Doug Walker walking through his neighborhood in a bathrobe and an ascot and a full on grin and unknown what his neighbors would think, knocks on a door, goes inside, you hear a bang, he walks back, gun in hand, through Doug Walker's neighborhood still, and back into his corner.
"By the way, where do you live?"
It gets better. Doug said at a con that his neighbors were pretty loud with music and such. When he went over there once to ask them to turn it down because he was filming something, they basically ignored him. Walking down the street with a gun and giving them a cheery wave when he went by their house was his revenge.
I would say Episode 44. How often does someone traumatizes Ask That Guy to the point that he is unable to respond to any of the questions and spends the majority of the episode cowering in the corner?
Similarly, the Love Martyr narrator constantly asking "True or False?" in episode 61 and very quickly reduces Ask That Guy to screaming and crying.
This Troper says Episode 45. When asked whether or no Santa should be sued, he talks about how Santa was bought out by Google, and since then Santa had taken down a lot of parody/satire stuff for copyright infringement. he simultaneously links Santa with Youtube (which pulled ALL of his stuff, which led to the creation of thatguywiththeglasses.com) and touts Blip Claus.
Episode 58. Ask That Guy's response to a question disturbs the Devil to the point where the guy talks over That Guy's explanation.
With Onions. Full stop.
Also his Take That to the internet's obsession with Justin Bieber. "Thank you! Thank you for so needlessly hating a little boy whose music you don't have to listen to!"