Here There Be Monsters - S1-E10
Plot hole: The female police officer has a theory that Johnny was the Strangler in the case the papers claimed he helped solve but this hardly makes sense. If she was researching him as was seen in the episode, surely it would have said something about Johnny being in a coma during the bulk of the murders since the story was about Johnny.
Forever Red - S1-E34
Plot hole: Tommy states that he and the other Zeo Rangers destroyed the Machine Empire's leaders and ultimately destroyed the Machine Empire except for the Generals who escaped. This is not true - Lord Zedd and Rita destroyed the Machine Empire leaders at the end of series 4, and the Space Rangers destroyed them again in Countdown to Destruction in series 6. The Zeo Rangers never destroyed the Machine Empire.
Suggested correction: How would Tommy know that? He didn't watch the show or know the ins and outs of what happened in space. This is what he believed based on his experiences on Earth. Everything you described is factually correct, but Tommy did not witness this. So, to his knowledge, he destroyed the Machine Empire.
Desertion of the Dinobots (1) - S2-E19
Plot hole: Perceptor discovers that the reason for their malfunctioning is because their Cybertonium has deteriorated after millions of years of being exposed to Earth's atmosphere. The key word here being 'millions'. This explains why the original Transformers who crash landed on Earth (4 million years ago) are affected, but newer characters like Perceptor, Powerglide, Hoist, etc. are affected despite the fact that they have only been on Earth recently.
The Powerpuff Girls Best Rainy Day Adventure Ever / Just Desserts - S2-E10
Plot hole: The children decided that they hated the Powerpuff girls in one day. Then how did they have supervillain costumes and a van? The mom said they had lots of time to prepare.
Plot hole: Xena is posing as a guard outside of Caesar's office. She knocks out the 2nd guard and throws him on the ground. Moments later, about 10 guards walk by, but no one notices the passed-out guard on the floor. (00:14:40)
A Gummi By Any Other Name - S1-E9
Plot hole: The Changing Hat has the habit of transforming its wearer at the mere mention of a name (or even a species type, as seen before when Sunni accidentally transforms into an ogre). However, when Calla impersonates Igthorn and faces off against him, she loudly says the name "Toadwart" and doesn't transform.
Plot hole: Bonnie is the anchor for the other side and feels when supernatural beings die. How come she didn't know Katherine wasn't dead? Did she never think it was suspicious that she never felt Katherine's body after she died?
Suggested correction: Katherine died but didn't go to the other side. So she didn't need to go through Bonnie. She went to hell to Arcadius. Bonnie is not the anchor to hell, we don't know how going to hell works.
After everyone finally realises that Elena had been possessed by her Doppelgänger Predecessor, It is actually shown that Katherine were more or less dragged away from Bonnie before she could crossover to the Otherside. So we do have some idea as to how one ends up in Hell.
Suggested correction: Katherine was a human technically when she died.
Technically, she was supernatural because she was a doppelganger, so she should've gone through Bonnie.
And even she was a traveller.
Sins of the Fathers Chapter 6: Framed - S3-E6
Plot hole: After Peter Parker is framed and arrested for selling government secrets to foreign organizations, he escapes police custody and goes home to retrieve his Spider-Man costume that was simply hanging in his dark room. If he was arrested for selling government secrets then surely the police would have searched his home and found his costume (as well as equipment) in the process. Since the police car was visible in front of his house, it seems very strange that police didn't search his home.
Beast Within - S1-E6
Plot hole: The mob hitmen are about to enter the Sweeny family's house to kill them when the police van arrives to move them to a witness protection safe house. In the next scene, the bad guys abduct Catherine and try to force her to reveal where the Sweenies have been taken. Why? They could very easily have waited and simply followed the van. (00:36:30)
Plot hole: When Lawquane spots the droids in the field, he identifies them instantly as commando droids. But as he had left the Republic Army shortly after the first battle on Geonosis (the one which started the war) and has lived as a farmer ever since, and since the commando droids are relatively new (see "Rookies"), how can he know what they are? With his lack of battlefield experience, he should simply call them battle droids.
Suggested correction: Though the films and series downplay this, the Star Wars universe has its equivalent of an internet/tv channels via the Holonet, which is how most normal citizens get their news. Even a deserter-turned-farmer would have reason to get Holonet access with his family, and he could have learned about Commando Droids that way.
Yeah, but would they also get information which might be under military confidentiality, i.e. which might be considered either too classified or too troubling to be made public knowledge?
While specific details on Commando Droids might be classified, that is speculation, and simply what Commando Droids look like and are called is probably not going to be classified. This is a galaxy-spanning war, where keeping such basic info secret would be very difficult. The Separatists might broadcast it for propaganda purposes, and the Republic might for propaganda purposes, or to warn their citizens of what the enemy's most dangerous troops look like.
The Would-Be Prince of Darkness - S1-E3
Plot hole: During the credits, Chloe said of the victim "coroner puts her time of death between 1 and 3am", and she does indeed ask Ty's obsessive fan / ex-gf where has she been during that timeframe. When she looks at the security tape, the timecode starts rolling at 22:18 and goes on "for 3 hours." That does not account for the time of the murder at all, she has no alibi for the second half of the suspected timeframe! Not to mention, she said she saw Ty kiss the victim. When could she possibly have seen that? It's unlikely that before 10pm Ty was already drunk and getting randy with the girl, with the house full of guests. (00:25:00)
Plot hole: Gaeta and Tigh both reference the fact that the Galactica crew computes the changes in stellar drift for FTL jumps and then sends out the info to the rest of the fleet for their use. However, when they fail to rendezvous with the fleet after the emergency jump, Gaeta realizes a mistake has been made and says that Galactica's info is out of date. This creates a major plot hole because if Galactica sends out the new info to the fleet, Galactica would always have the most up to date info for FTL jumps. The crew would be able to solve the lost fleet crisis by simply reloading the last coordinates that Galactica sent out and jumping there where the fleet would be waiting for them. There would be no need to go back to the previous coordinates and recompute the jump.
Plot hole: Because Katara lost her mothers necklace, Aang made one for her and she puts it on. But when they reach The Fortunetellers village, Katara is not wearing the necklace, and no one notices, not even Aang.
Plot hole: When John inserts Cameron's CPU, she restarts nearly instantly. She recognizes John right away and speaks to him by name. Yet seconds later, we see through her eyes as her system reports recognizing him, but she already does.
Plot hole: Series 2, Episode 11, The Agenda (1). The Tripredacus Council explains that Ravage will be able to find Megatron and the others by tracing the transwarp wavefront back through time to its source. If he truly did follow it back to when it started he would have arrived moments after Optimus destroyed the alien weapon in "Other Voices: Part Two" which created it, yet he arrives considerably farther in the future.
The Best Years of Your Death - S1-E3
Plot hole: In the chapel, you can see the heads of those who tried to cross Harriet (the mad matron) preserved in formaldehyde. How did she get hold of so much of it? Wouldn't her husband or the headmaster be suspicious?
Plot hole: (Ep. 5) The weapon Stephen finds in a desert is a H&K G36. He states that it's not a military weapon and is mainly a mercenary weapon. The G36 is used by several police and special forces units in the world, including the British SAS, which could suggest another nation's or British government branch's involvement. Comment was probably made to deepen the intrigue of the season plot.