Lara: Stop it, Lara. You're starting to sound like Dad. It's like they're the remnants of some lost civilization! ...okay, now I really sound like Dad.
In a collection sidequest, Lara has a Nerdgasm over finding a jade horse from the Kublai Khan era. Further investigation reveals the words "Made in China". You can practically hear the disappointment in Lara's timid little giggle. Another one of the collectibles seems like something exciting at first... until Lara discovers a price engraving of "49.95."
If you wait around the old PT boat for a bit before going to link up with Alex, Sam will accidentally fire off one of the boat's still-functional machine guns. While responding to Reyes's admonishment to be careful by saying she knows what she's doing.
At one point on Shipwreck Beach you can talk to Sam and asks how she's passing the time, and she's reading an old copy of Robinson Crusoe and commenting on how it's a cruel irony.
Some of the conversations between the bad guys that you can overhear are pretty hilarious.
Returning to the Shantytown can lead you to two guys arguing about borrowing a book in return for smokes.
In the same area, Lara can come across two Solarii searching for something... which is revealed to be their pet rat, Sprinkles.
As an example of how much the Solarii have come to fear her, one conversation consists of a cultist freaking out when his partner starts talking about where "she" could have gone. Ends up he's not talking about Lara, he let his pet pig out and can't find her. Bonus points for Lara happening to be right by them and (as players are want to do) killing them after their conversation.
If you head back to the beach after heading to the final level. Two mooks are discussing food. With one mentioning his skill at cooking a mixed meat dish, listing off what he uses, the other is very receptive to this until his partner brings up the fact that he also incorporates sea gull meat.
Her somewhat dramatic voiceover when she's first filming Lara.
Reyes and Alex are trying to fix something, with Alex insisting that it's not an electrical problem (and therefore not his responsibility). Then Reyes has him pull a lever and it does turn out to be an electrical problem.
At one point, Grim talks about the time he HEADBUTTED the freaking Loch Ness monster.
And in that same section of footage, we see Reyes pulling Roth offscreen by the hands, but not before he glances at the camera, prompting Sam to quickly hide.
The image for the "Pistol Expert" skill. Both Lara and the enemy she's threatening with a pistol look too stoned to realize what's happening. (Lara's even looking away from the gun, as if she can't bear to watch herself pull the trigger.)