I'd say the three people that are both loved and hated the most, in general, are Cena, Batista, and Triple H, for the following reasons:
1. Too much time devoted to them. Cena wins in this category. This past year, nearly everyone on Raw had to take a backseat because it became "the John Cena show". Batista gets this directed at him because of how often he's involved in the title scene, which is annoying. Triple H gets this because he's virtually never taking the low road. If there's a chance for him to be in the main event, you bet your ass he's in there.
2. Immortality. Batista is the least involved in this. They make him seem like a tough guy, but they've even had him being beaten by MVP and such. He's "immortal" to the lower guys on the roster, but otherwise not. Triple H recently made Snitsky, Mark Henry, Umaga, and others look like chump change despite how the WWE wanted to make them monsters. John Cena does the same thing. They try to make the rules "if its Cena or Triple H, it doesn't matter, because its them". They wouldn't think twice about having the two of those go through 90% of the entire WWE's roster on all 3 shows combined.
3. Character. For the most part, people like Triple H's character, especially when he's involved in a DX segment. However, Cena is far too demanding, and it feels like he's trying to get a pop with every word he says. Look at his segment on Raw the other day. He nearly cried when he was being booed after ever sentence that was structured with exclamation points, hoping that it would receive a loud roaring cheer. Cena ends up being the "public spectacle" type of kid who you feel is trying too hard for attention. Batista, on the other hand, is hated because he has a total lack of character. The guy comes out, smacks himself on the chest a few times, and that's it.
4. Moveset. Easily, Triple H has most versatile set of moves. Cena and Batista are both criticized for having a limited amount, and its justified I think. Though Cena COULD do more than Batista, it seems he's too stubborn to want to try to go outside the box. He might've hit a comfort niche and is too afraid to try anything new, despite people like HBK who is past his prime but he's now adding submission moves to his arsenal (but comparing Cena to HBK is like comparing leftovers to a buffet).
All in all, I think the only reason Batista isn't hated as much as Cena is because of the fact that Cena's there along with Triple H. If someone's in the spotlight, they're going to receive criticism (Orton when he won the title, Hardy now that he's receiving a push, etc). However, Triple H receives a lot of heat for his backstage politics, Cena receives a lot of heat for being given an aura of invincibility and over-importance, and that takes some of the heat off Batista as people are more prone to argue about the two that are shoved in their face more often. Look at this year's Royal Rumble. These three were the final 3, and made they made it look like Kane and Umaga were worthless. Then, Batista is eliminated, and the spotlight goes to Cena and Triple H. Batista is clearly the bronze medal to the WWE, so there are 2 other people to take some of the bullets first. If Cena and Triple H weren't as controversial, Batista would be ripped to shreds even more than he is now.
This isn't in support or directly in offense to any of the 3 guys in particular. My personal opinion is that Cena and Batista aren't talented enough to be the top men in the company, and that they should be toned down a lot more. As for Triple H, he's talented enough to be a top guy, but he needs to look out for more than just himself, and then I'd respect him a little more - like I used to. So yeah, all three annoy me in ways and entertain me in other ways, but I never really get too heated about them unless they're trying to shove them down my throat.