The revelation that President Flavia has had the Doctor and his tendency to agitate for removing the Non-Interference Laws written into the Presidential manual. Yes, he is quite literally that predictable.
At one point near the start when most of the Doctors are together, Four says "I'm sure I can think of something." Seven corrects him: "You mean you're sure we can think of something." After a brief pause, Four simply replies "No."
From the same page: Three tries on Six's coat. Six and Peri are amused, and Sarah Jane looks like she's about to retch.
Seven introducing Two to Davros:
Seven: This is Davros— Two: Oh! Heh heh. (he shakes Davros' hand) Seven: (whispering) He's the fellow who created the Daleks. Two: Oh... ahem. For shame.
Seven and Three chastising Nine, culminating in Six's first appearance:
Three: Lying about your age, unhealthy relations with your pretty young companion... shaved head... leather?? Nine: Hey! Seven: Sounds like a second mid-life crisis. Three: Second? Seven: Oh yes! I had a really bad one back when I really was only 900 years old. (Six appears) Six: Mid-life... mid-life crisis??? MID-LIFE CRISIS?? Of all the confounded— Seven: —Speak of the gerbil.
Page 8: Nine and Rose start arguing Like an Old Married Couple after she finds out about Susan being his granddaughter, and some of the other Doctors and companions take notice.
Rose: Who's her grandmother then? Or did you just drop her off somewhere, sometime?? Nine: Rose, this is not the time— Ace: (to Seven) Gordon Bennet! Drop me off before you pick her up, alright? Peri: (to Six) D-D-Doctor... are—are you and she... Six: I should think NOT, Peri. That would be in poor taste!
When Peri and Turlough carry Nyssa away from the crossfire of a Dalek fight.
Peri: Where are we taking her? Turlough: I don't know. Preferably off the battlefield.
After the 10 Doctors manage to break the Dalek conditioning out of Ten, they tell their companions about what they did... and they tell it as if each of them was the fundamental piece and the others were just an obstacle. Which, given that they are the same character, is not exactly a lie.
Six gets angry with Four when the latter questions his motives for helping the Renegade Daleks and pushes him into a vent. Four's answer is hilarious:
Four: You give new meaning to self-loathing.
Six's answer is just as funny:
Six: Watch it, or I'll go back and turn the Pharos dish myself!