Todd's landlord threatening to cut him while brandishing a hammer.
When Todd is being questioned by Zimmerfield and Estevez about Patrick Spring's death, he is asked if he saw anything weird that day (he also remembers when he apparently came across himself from the future — and almost mentions it but decides not to):
Todd: Yes— no...m-maybe, I don't know...
Estevez: Are you aware you just gave every possible response to that question?
Then after Dorian is killed and Todd is arrested, he is let go after no evidence is found to convict him:
Todd: So I'm not a suspect in anything?
Zimmerfield: You're a person of interest. Permanently. Even though you're not necessarily an interesting person.
Todd: ...That feels unnecessarily rude.
After Bart chases down Ken with a machete after thinking that he is Dirk Gently, she finds out that she's got the wrong guy:
Bart: What, are you kidding right now? Then why did you run?!
Ken: You have a machete?! And you killed Red!!
Bart: Why didn't you say "I'm not Dirk Gently"?
Ken: BECAUSE I DON'T KNOW WHO THAT IS!
The introduction of the Rowdy Three:
Todd: What's going on? Dirk: The Rowdy Three! Todd: There are four of them. Dirk: I'm wildly aware!
The entire bridge scene during episode 2.
Dirk and Todd hope to get some answers from the big bad, and discover he is as clueless about what is going on as they are.
Dirk: Aww... nuts!
Todd and Ken's wordless exchange in the final episode as they finally cross paths: an exasperated shrug that says so much: "They're nuts, right?" "I know, right?"