During the Embassy mission, you can use Aiden's Poltergeist powers to take out the security cameras and open the safe containing the Sheik's secret documents. However, there is another option: possess the Sheik himself, walk up to his office and take out the documents to read. The guards won't give you any trouble because, well, you're the Sheik. The sheer audacity of this plan is hilariously awesome. You even get a trophy for it: Possessive Spy.
In "Homeless", Jerkass bully Ed's enormously satisfying Oh Crap reaction when he realizes that he's unarmed, alone, and that the woman who just beat up his three friends bare-handed is now holding a baseball bat.
Goth Jodie's tantrum at the start of "Like Other Girls" as she using Aiden to smash up the apartment and Cole is just watching on the camera and berating her over the tantrum. And her random scream at Nathan when he tells her she can't go out.
Play the electric guitar, and watch Goth Jodie loudly play with the intent to damage poor Cole's eardrums. Made even funnier when Cole simply turns down the volume on his monitoring equipment.
In "My Imaginary Friend", little Jodie can pick up the phone upstairs and launch into a pretty good imitation of an adult woman calling her friend.
Jodie: Hello? [Beat] Hi, how are you? [Beat] I'm fine, thanks! This weather is terrible. [Sighs] All this snow! I hope it'll end up soon. [Beat] Kids are so difficult when they can't go outside!
When Aiden's influence makes the phone's speaker make a creepy crackling noise, Jodie is only momentarily taken aback before giving an exasperated little roll of her eyes.
When Aiden is trolling Jodie before her date with Ryan. He locks her out of the apartment, piles all the chairs up onto the table, and throws cushions onto the floor like a disgruntled child. Veers into Tear Jerker territory if you take it too far. Ryan will leave, and Jodie will end up crying.
This can lead to a moment that's equal parts cute, sad, and funny, Aiden picks up the wine bottle and pours Jodie another glass
Really, the simple that Aiden, a supernatural being who can kill you by choking you to death, dropping something on your head, or forcing you to commit suicide, and of whom several people are justifiably afraid of, is throwing a temper tantrum is hilarious in and of itself.