Angela: Do I have to take the rest of my clothes off or can I leave them on? John: ... Angela: John? John: I'm thinking...
When Constantine busts into Papa Midnite's, he belts the bouncer and marches downstairs. Chas stands over the unconscious bouncer and giggles: "Who's the rat in the dress now, huh bitch?"
As Constantine ascends to Heaven, he flips off the Devil. Doubles as one of the most awesome moments in the movie.
It's important to realize this is as he's being dramatically pulled up to Heaven, and he does it in perhaps the most off hand manner possible, though it's complete with slow motion.
In the novelization, it is actually God controlling Constantine's hand, which is even funnier.
The very end of the movie, when Constantine punches Gabriel in the face instead of shooting him/her.
The funniest bits of the above scene are the couple of seconds it takes for pain to register to Gabriel (during which he whispers "wow" when he sees the blood from his mouth), and as Constantine keeps walking while he calls after him with his comments.
This moment in the car:
Constantine: Corinthians goes to 31 acts in the Bible in Hell. Angela: (in disbelief) They have Bibles in Hell.
Most of Satan's conversation with Constantine is hilarious, what truly sells it is the casual tone which John uses when talking to Satan.
Constantine: So how's the family? Satan: Family's doing fine. Busy, busy, busy! Need a vacation.
Not to mention Satan's churlish dismissal of Mammon meeting with Gabriel in the next room ("Urgh. No accounting for taste, really."), to his impossibly childish "oh, oh, not quite there!" lighting of John's last smoke.
Speaking of smokes, his affable encouragement of John to have one.
"Oh, go right ahead; I've got stock."
And his giggling amusement when Gabriel hurls some archaic titles for Satan at him like she's a Medieval inquisitor. His reaction?
[nostalgic] "I do miss the old names."
Angela's faint exasperation at not getting kissed three times in a row. It's blink-and-you'll-miss it, but watch her face each time Constantine leans in.
The scene in Angela's apartment. It's nice to see Constantine stop being mean and actually teasing her.
Angela: If this is some kind of spell, don't you need candles and pentagrams? Constantine: Why? Do you have any?
At the hospital early on, when the doctor is explaining that Constantine's lung cancer is terminal, and he lights up a cigarette.
It's both awesome and hilarious how John intimidates Balthazar into spilling the beans about Mammon's plan, by threatening him with... Absolution of all his sins, thus sending him to Heaven when he dies, which for a demon like him is And I Must Scream levels of horrible. Even better is once he breaks and tells John everything he knows about the rest of the plan, John reminds him that forgiveness can't be given unwillingly anyway, and that he bluffed the whole thing!
Constantine: [Intensely quiet] How?! How's he doing it?! Balthazar: [Near tears] N-no... no! Constantine: [Full shouting preacher mode] GRANT YOUR CHILD ENTRY INTO THY KINGDOM! IN THE NAME OF THE FATHER!... AND OF THE SON!... AND OF THE HOLY SPIRIT!... AAAAAAAAAAAAAAMMMMEEEEEE- Balthazar:SANGRE DE DIO!... The blood of God... Constantine: ...He found it... [Casually puts away his Bible] By the way, you have to ask for absolution in order to be forgiven... Asshole. [Smirks]
Constantine: Jesus didn't die from being nailed to a cross. He was killed by a soldier's spear.
Angela: The Spear of Destiny. I'm a Catholic, John. I know the Crucifixion story. note Made even more funny in that they're both wrong - Jesus had already died on the cross when the Roman soldier speared him to check if he was still alive.
After Gabriel tries to attack Lucifer and fails, Lucifer glances up briefly, like he's double-checking to make sure God's not actually going to smite him.
