In Curse of the Crimson Elixir, Alex splits the party up. His only reason for sending Riku to partner up with Major Armstrong is so he'll get crushed by the Major's Bear Hug when he's relieved to see them again.
Wings of Time has a few, mostly from Ed.
The first Dalton boss-battle is finished within seconds when Ed gets called short and becomes the Hulk to his Loki.
After bringing Alex back from the dead, Ed suddenly learns he hasn't gotten rid of Joumae.
In Dark Renegade, Jak, Daxter and Alex are all thrown out of the Fortress by the explosion. Unlike Jak and Daxter, who bounce off an awning in a cartoony fashion, Alex simply lands on his head, which then (sadly, offscreen) proceeds to disorient him for several minutes.
While trying to head to the sewer in an elevator while on a mission for Krew, the three of them start getting curious about the loud noises outside once they've stopped. They open the door... to see around a hundred Metal Heads and Heartless waiting directly outside.
Daxter: (as the enemies start to attack) UP! UP! WHERE'S THE FREAKING UP BUTTON!?
In Chapter 12, Alex contacts Jak over communicator to check up on him. When Daxter answers that they're meeting the girl at the racing garage, Alex casually mentions it's Keira. Cue loud crashing noises and the city klaxons suddenly beginning.
Okay, he thought, that's a shotgun.
And then he can't hold back a squee after causing a ridiculous amount of chaos in the space of five minutes and managing to get away unscathed.
Essentially, Alex is suddenly a goldmine of hilarity.