10. Sherry Palmer (24)
Okay, I know that pretty much every person on the internet hates Sherry, and I don't blame them. I mean, that's the point of her being a villain, to make people hate her. And I get why Logan may have fans and she doesn't (hell, why ANY villain has fans and she doesn't). Most villains were striving towards a goal, in Logan's case, he did bad things, but in his heart, he believed it was for the good of the nation...at least until it came time to cover things up. With terrorists, they want to terrorize, that's what they do. With bureaucrats, they're just trying to do their jobs in the confines of the law. With Sherry...everything she did was completely self-serving and b****y, and a lot of people aren't going to be able to identify with that and they're going to hate her as a result, because we all know someone like that, just like we all know a Chloe. The person who even when they're being nice, they're doing it because they want something out of that. Hell, I can admit that I've been that person on occasion, so perhaps that's why I like Sherry so much.
Season one, it's interesting to watch the early episodes, because yes Sherry's a bit b****y, but she's just protecting her baby boy from David, who she makes the case is trying to use Keith to gain political support. But as the season continues on and their roles reverse, Sherry becomes more and more awesome. She lets it slip that she's trying to protect David's career while only using the GUISE of defending her son, which is ice cold if you're Keith, and I don't know how he could ever speak to her again after that. But when Keith gets evidence to use against the bad guys in this scenario (which would insulate him from any planted evidence in the murder of Dr. Ferragamo), there are three options on the table: one, reveal everything...that's David/Keith's choice. Two, hang onto that evidence and use it to blackmail the bad guys...that's Mike's choice, and while sketchy, it's still smart, given the kinds of people being dealt with. The third choice is Sherry's, which involves destroying the evidence and pretending nothing happened and sweeping everything under the rug. The third choice serves no purpose other than Sherry being worried that revealing the evidence, or even having it around, would damage David's chances at becoming president. So she destroys the tape herself...only to find out that it was a decoy and she was being tested. To quote Indiana Jones and the Last Crusade...she chose poorly.
So at this point, she's on the outs with David. She's not trustworthy for various reasons (like covering up Keith's self-defense killing, and then trying to destroy evidence), so she knows she needs to regain some ground. After all, she wants to get into the White House more than anything. So she tells one of David's campaign employees to have an affair with him. She physically condones this, because she knows she can control Patty and still be in David's inner circle, in a way. Well, he sees through this and fires Patty and Sherry is in an even bigger hole. But that's not going to stop her. She may not have pull with the president, but as long as she makes it into the White House, she'll still have some degree of power. But when David pretends to be dead in order to protect Kim...Sherry's not having that. She's not letting David f*** up her shot at the White House over one girl. So she leaks the fact that he's alive to the press...and David DESTROYS her. I almost wish that he'd slapped her, because then we would've had physical violence towards Sherry in every season she was in, which you know the audience was rooting for. As mentioned in David's write-up, the level of rage he shows towards her and the careful delivery of his final line (coupled with her "DON'T YOU WALK AWAY FROM ME DAVID!") is an amazing scene and really highlights David as a great character in relation to an equally great character of Sherry.