Plot hole: Why is that shark machine even there? The only reason it's there is to help the plot, and I don't see how it is of use to anyone in the corporate world. If the shark just ejects the fish it turns into fish heads out to sea, there is too much chance they will be ruined by carnivorous fish or weather before they are picked up. And fishing companies should know better.
Plot hole: According to the phone book the name given was "M. Horowitz" but when Mary mails he first letter to him she already knows it's "Max."
Plot hole: There are two cars driving behind the EPA truck containing Marge, Bart, Lisa and Maggie. When Homer uses the bulldozer to try and break the family out of the truck, the two cars behind the truck don't notice the bulldozer trying to destroy the truck. There's no way they couldn't have not seen the bulldozer since they were just behind it. (01:00:05 - 01:00:40)
Plot hole: Cruise leaves Lugnut to go buy he and Coupe some seats and mere seconds after leaving, Coupe appears in the scene and talks with Lugnut. Coupe asks if he has seen Cruise, but even if Cruise had already left to go buy tickets, Coupe would have already seen him when approaching Lugnut since she only arrived seconds after he left. (00:09:15)
Plot hole: I can somewhat understand that in a kiddies' show all aliens can inexplicably speak English - but using Terranean (i.e.: Arabian) numbers as well? While Tetrax's computer uses alien runes, the readout on Gluto's holographic HUDs use Arabic numbers - somewhat a bit too deliberate a producer choice to emphasize intergalactic communication.
Plot hole: During the final scare event, Mike gets a perfect score because Sully broke the simulator to allow the 6th scarer to get a perfect score no matter what. After the contest, the simulation resets and Mike pretends to scare the child in the simulator and it registers a perfect score on the scoreboard for the 6th scarer when it should really have registered a score for the 1st scarer, because the simulator had been reset.
Plot hole: Even if Chicken Little was tagged out when he hit home plate, the game was already tied so his team would still have a chance to win the pennant.