(spoilers of TES series below!)

Lore-wise, I'm led to believe that the Champion of Cyrodiil is the strongest protagonist in TES series, seconded by Nerevarine, than Dovahkiin, The Eternal Champion, and The Agent in turn.

I like to ignore guild quests because it's simply implausible that one character becomes a guild master of every major guild in one province. I only took main quests of the vanilla game and its expansions into consideration.

The Agent was merely a competent agent.

The Eternal Champion was only a talented warrior who *barely* defeated Jager Than using the staff of magic.

Dovahkiin saved Tamriel, but Aldu'in is nowhere as powerful as enemies that Nerevarine and CoC defeated. (I've not finished expansions, so you could correct me if Dovahkiin has accomplished something greater)

Nerevaine killed 2 demi-gods and possibly killed another demi-god(Vivec has gone missing after Morrowind). The tribunal was powerful enough to defeat the avatar of Mehrunes Dagon who invaded morrowind and Dagoth Ur many times in red mountain, but Nerevarine had possibly become more powerful than all three combined, as the tribunal was no longer able to contain Dagoth Ur's power by Morrowind's time frame.

Nerevarine also defeated Hircine who sought to test him. I'm not sure if it was an avatar of Hircine or his real body, but even assuming its the former, it's still a remarkable feat to defeat a daedric prince in his realm.

The relative power of an avatar of Deadric prince compared to their real body is also debatable. I think there is not much difference, because Akatosh's avatar was able to defeat Dagon himself.

Then there is CoC. He didn't do much in TES IV's main quest, but in NoTN and Shivering Isles he defeated Umaril(deemed almost as powerful as a daedric prince according to some NPC) and defeated a Daedric prince in his realm, where one is nearly invincible. I don't think his position is disputable since he has become... you know, a daedric prince.

What do you guys think?

I think the Dovahkiin is the strongest, being part of Akatosh and all.

The Champion of Cyrodiil did not defeat Mehrunes Dagon, he just carved through a horde of enemies and went dungeon-diving for Martin so Martin could defeat Dagon. He's definitely the weakest, but that's what made him special. He wasn't chosen or anything, he was just a regular ole' guy who stood up to the impossible to save the world, and he did.

The Nerevaine did defeat two demi-gods, so I'd say that he is specially powerful, being blessed by the Divines.

The Dragonborn is literally a fraction of Akatosh, with the soul of a dragon. He was chosen before his birth to destroy the firstborn of Akatosh, a demi-God dragon-lord who's destiny was to destroy mortal existence. I'd say stopping the world from ending when the Divines themselves wanted it to makes him far stronger than a warrior killing two demi-gods and a mortal champion who fought hordes of Daedra.

And the Eternal Champion and the Agent were also just guys. So yeah.

That's because the ultimate fate of the Dragonborn has yet to be written. All signs point to apotheosis a la Talos. And we all know what Talos's reading is on MK's Scouter.

And how exactly is Alduin himself not a demigod? Alduin literally has only one weakness, and it was lost to time before an Elder Scroll revealed it again.

And technically, the Dragonborn is a demigod as well.

Well, no, at least in terms of power. I'd say the Agent is the "weakest", with the Eternal Champion above them, and the Nerevarine and Champion of Cyrodiil far above those two.

"Alduin is nowhere near as powerful as the rest"

Again, no, he's the world eater. The other threats didn't exactly promise to bring about the end of the entire world, did they? And yes, by the end of the expansions, you would have defeated the "first" dragonborn, who was also very, very powerful. Powerful enough to take control of an entire island, something even the Last Dragonborn can't do by the end of the quest. Then there's Dawnguard and Harkon, a powerful pure-blood vampire, who was going to block out the sun.

Unlike the rest of them, who had to work their way to their power, the Dovahkiin was born a demigod so they can take on another god. They still had to work at attaining power, but it was far easier compared to the other protagonists. There's a reason so many theorize that the DB might ascend to godhood before the next game.

Now, is the Dragonborn an overpowered individual that just reeks of wish fulfillment in a way that the others managed to pull off better? Yes, and while there are reasons for that it still made playing the LDB annoying for me. Let's get more Agents or CoC's, please. (The Nerevarine in particular did the "chosen one" thing better)

The dragonborn is the most powerful.

Least powerful, no. Least interesting, yes I'd say so.

Im not a lore [censored] but imo the nevarine was the most badass killing gods and all. Then the dov destroying the eater of the world. A very distant third is the champ who was basicaly a really fast running errand boy for the last septim spawn. Without martin and his blood the champ would have been smooshed under dagons hillarious bannana hammock.

Champion of Cyrodiil wasn't necessary powerful (prior to becoming Sheogorath) but the CoC definitely achieved more than any hero. The CoC was pretty much the backbone that put an end to the Oblivion Crisis and did everything (besides defeating Mehrunes Dagon). After that, did the CoC defeat Umaril the Unfeathered; and then Jyggalag, Daedric Prince of Order. And like another said, it makes it even better was that the CoC was simply a normal person. But even then, the CoC becomes the Daedric Prince of Madness. I consider that more powerful than any other hero.