Don't get me wrong, I really like the show. I couldn't stop watching it and always wanted to see the next episode, it didn't take too long to go through all eight seasons and it never stopped being interesting. The reason I'm making a list of things I didn't like about it is because I like most of it.
So, here's some decisions I kinda didn't like that the creators of the show made. Let's start with the ones a lot of us might agree on: Killing of favorite characters. I'll have separate paragraphs for each one.
Warning: Contains spoilers
1.) David Palmer. I bet you all expected him to be on the top of the list. He is like the secondary protagonist to the series, one of the most likeable and sensible characters in the show who always played his presidential campaign honorably (unlike his wife). Even after he stops being president he returns to help in Season 4. But in the very first episode of Season 5, he's the first death of the season. I understand that was done to show how evil Logan's conspiracy was, particularly Graem and Henderson (who were most directly responsible), and how far they were willing to go, but the whole first season was about protecting him from the terrorists who wanted to assassinate him, and he survived Mandy's attempted assassination of him in Season 2.
2.) Bill Buchanan. Like David Palmer, one of the greatest and most sensible characters in the show, always trusted that Jack knew what he was doing and broke up arguments when CTU members fought amongst themselves. A key figure in the operation to bring down the corrupt officials, he ends up sacrificing himself to enable the defeat of Juma. The best that can be said is that his reputation will forever be a good one, as opposed to the bad reputation he was unjustly threatened with in Season 6.
3.) Edgar Stiles. I thought he was pretty cool, and he is unexpectedly killed in Season 5. Which forms the basis of the "hate" in my "love/hate" thing for Bierko (the "love" only coming from him being played by Julian Sands, who I know as Valmont in Jackie Chan Adventures)
4.) Milo Pressman. He was really cool, and was like a replacement Tony in Season 6, but he gets killed by Cheng's guy.
5.) Richard Walsh. He only appeared in two episodes before Gaines's men kill him, but he was pretty cool, and Jack described him as his "only ally".
6.) This one's going to sound ridiculous, but Victor Rovner, the first character to appear who informs CTU that David Palmer is the terrorists' target. He is killed offscreen by the terrorists after. I was hoping to see more of him because he's played by Jeff Ricketts, one of the two Hands of Blue in Firefly (I never see him or Dennis Cockrum in enough stuff). Interestingly enough, the last character to die, Jason Pillar, is played by Reed Diamond, who also appears in a Joss Whedon series (Mr. Dominic in Dollhouse).
Second, other fates for my other favorite characters that might have been preferable if they had died.
1.) First and foremost, Tony Almeida. He, David Palmer, and Bill Buchanan were my top three. After his death in Season 5, he is resurrected in Season 7. Although working with the enemy at first, it SEEMS he's working undercover to help Bill expose the corrupt officials. But then it turns out he's playing both sides for personal revenge. Sure, Jack's been vengeful too, but Tony killed innocent people, like Larry, and tried to frame an innocent man as a terrorist, which had me hating him and wishing eternal damnation on him. And he'll probably receive it too once he eventually dies in prison, coz he never redeems himself and is last seen calling Jack a coward. At least David Palmer was the good guy we loved until the end, and Bill took it a step further with his heroic sacrifice. What Tony got, made their deaths look like they received a pair of wings and a title of Prince.
2.) Henry Taylor. I kinda liked him, mainly coz he's played by Colm Feore, but after Olivia kills Jonas Hodges and President Taylor refuses to cover it up and has her sent to prison, he goes out of his way to hurt her when they divorce, and doesn't return in Season 8.
At least Mike Novick and Aaron Pierce are all right the last we see them.
Lastly: Mandy. The fan favorite villain, and one of the first two to appear (other being Nina, who we don't know is a villain until the end of Season 1). She makes unexpected appearances. Disappears after the third episode, returns at the end of Season 2 hired by Max to kill David Palmer (but fails), then surprise appearance in Season 4 as the one who told Marwan where Heller was, and in the end leads them to Marwan the final time.
Following this she gets immunity from her past and present crimes, but plenty of us would have liked to see her violate that like Nina did and continue her life of crime, possibly leading up to her ending up like Nina. She was intended to appear in Season 7 in place of Cara Bowden, but the decision was dropped. It WOULD have taken quite a bit of heartache out of Tony's FaceHeelTurn. She was also intended to appear in Season 8, but they decided against it because "It felt like a sensational move and we chose not to go down that path". So what, they don't want to please the fans? Is that it?
I really hope Mandy appears in 24: Live Another Day. And its existence is the reason I'm not complaining that they didn't give Jack a better ending than having to go on the run like in Season 4.
There are two more things that aren't so much complaints as a "I can't understand how it happened". The first was Suvarov turning out to be a villain by helping Samir's terrorist cell, after he seemed like such a good guy in Season 5 and was only defending his country in Season 6. The second is how Logan turns up alive in Season 8 when Martha cutes an artery and he flatlines in Season 6, which would imply that he was dead, how did he survive?