In general, I've loved-to-hate the Thalmor throughout my time playing Skyrim, but recently...I'm finding that harder to do. Part of it is just how polite and agreeable they are during the Embassy infiltration. There's just something cute about the guards apologizing and saying that they're on duty, for example.
But there's more to it. I think most dedicated players are aware of the Thalmor's eventual goals, correct? They intend to "unmake" the world, as indicated by Ancano during the Eye of Magnus incident. Now the thing is...I agree with them. At least in real life. I don't know if I'd want them to destroy the TES universe, but if such a group existed here? Yeah, I'd join them. Granted, I don't appreciate their lack of any apparent intent to extend their godhood to non-mer races, but nonetheless, I can appreciate their desire to escape reality.
Of course, there's probably a lot more to the Thalmor than we've seen, given MK's remarks on the subject. As far as we know, they're a cult that wants to destroy the world and become gods. That's a pretty significant threat, but it's hardly "utterly unknowable" and "without a doubt the most powerful threat Tamriel has ever faced". (Not perfect quotes, but that's the jist of it.) So I would guess that there's something really weird going on in the upper levels of the faction. Possibly something to do with Sithis. He is, after all, basically who would benefit most from their plans succeeding.
Anyway, I just thought I'd mention this little dilemma of mine. I want to hate them, but I almost can't at this point. Still, they don't show any respect to the Dragonborn, so I can at least hate them for that.