During the mission to break into the Virility Factory to find the Succubus, Dante questions Kat on how she met Vergil and she tells him that they met in Limbo. Dante then asks why she was there, and she responds that she was escaping the nightmares. Dante's cutest WTF face ever.
Dante: You came to Limbo to get away from the nightmares? Kat: Yes. (Dante silently mouths "fuck me" when Kat walks away)
During the boss fight with Bob Barbas, you can see a bit on the newsticker.
Newsticker: Bob Barbas voted the world's sexiest news reader.
Just about everything in this boss fight is bound to make you laugh or chuckle:
Bob: You think you're cool? How about I kill you and piss on your corpse for cool points?
This gem inside the fake news segment:
Bob: ...spreading sexual diseases of the unholy kind.
Dante: Ain't that the best kind, Bob?
The fake news reports are amazingly daft that one can't help but laugh at how obviously false they are.
Even better, he does Bill O'Reilly's "We'll do it live!"
A nice Oh Crap! moment for the player when the three are invading Mundus's building. As Dante heads up, he tries to remember which floor to stop on, thinking it's 105. We then hear Kat going over the plan telling him to stop on 106 and not 105, which is infested with demons.
The Vergil-centric DLC isn't funny at all. The construct of Dante formed by Vergil's subconscious and insecurities is a spiteful, cruel individual who always looked down on his brother. What is funny: the only thing it has in common with the actual Dante is that it still cracks horrible puns.
Hollow Dante:(after Vergil flings a bus at him) Ahh, I hate public transport!
Dante is trapped in Limbo inside a church, and has to make it to the window at the end of the aisle in order to escape. As soon as Dante is about to reach said window, Limbo stretches out the aisle, and this happens multiple times. After Dante eventually escapes, he treats us to this pun:
Dante: That seemed to drag on forever...Church.
After beating Vergil in the Definitive Edition, the same ending plays out, but with one major difference. As the camera pans towards Dante, instead of his eyes glowing with power, Dante escorts Kat out of the area, and attempts to grab her ass on the way out. Way to kill the drama, man.