Everyone hates the Thalmor, bro. Also, I'm none to keen on Ulfric's murderous band of treasonous thugs, either.
Though, the bulk of my hate in Elder Scrolls is saved for Altmer, specifically. I haven't met a single good one.
The first time I went Stormcloak, because, well, I was still pissed at the empire for trying to, y'know, execute me at the beginning of the game. Also, fuck the thalmor. Sideways. With a chainsaw.
Eeh, I wouldn't have a problem with the Stormcloaks if they weren't giant god damned racists and think their dinky, barely-working militia could actually pose a threat to the Thalmor and/or the Aldmeri Dominion. Those two are the real threat, and only the Empire has the equipment to actually bloody
deal with the Aldmeri Menace.
I will always be disappointed that vanilla Skyrim doesn't come with a "take over yourself" option like you've got in New Vegas. First off, if your Dragonborn isn't an elf of some sort, then you're likely a shoe-in for Emperor, and that's before you kill off Alduin and save the entire god damned world. Think about it, all the Emperors up until Martin Septim were of dragon blood, which is why the Amulet of Kings worked the way it did. Being a creature of near godlike power, you could easily strike up the same deal with the same god and make a new Amulet of Kings. You're human, you've got dragon blood, and then you'd have a new Amulet of Kings. If you do all this
after killing Alduin, then everyone would fuckin rally around you as, more or less, the bloody messiah, even moreso than Nerevar.