Sith'ari, why the hell do you constantly lie and twist facts?
1. You're the biggest liar here, and quite clearly a hypocrite too.
2. It's funny how whenever you call me a liar, you always fail to back that up.
3. Where did I lie or twist facts?
Yoda being called the strongest up to that point is NARRATIVE and approved PERSONALLY by Lucas.
Where?
The RotS novelisation statement that you refer to is narrative dependant on invalid events, and thus is also invalid. It is also Yoda himself miraculously coming to this belief, not the omniscient narrator factually stating it...
And are you trying to say the Jedi are so much weaker than the Sith?
No, that's not what I'm saying, what I was saying was that even if Yoda was the most powerful jedi ever, you cannot absolutely prove that the most powerful jedi ever would have to be stronger than the most powerful sith. And jedi tend to be weaker than sith, yes.
The NEC confirms Palpatine as the strongest Sith as of ROTS
The NEC is written by a historian inside the SW universe, he's basing that opinion off of inconsistent and sometimes inaccurate historical material, his opinion is in no way better than mine or your's, it's actually most probably lesser. The point is, that does nothing in proving that Palpatine was the most powerful sith lord ever.
the Dark Side sourcebook
This argument has been constantly defeated, power in that context wasn't purely related to combat prowess.
and DE Sourcebook confirm him as well
I searched through the DE Sourcebook, the quote was nowhere to be found. Nobody's claiming responsibility to originally coming up with that either. In other words, the quote doesn't exist, it's a lie.
You need to get off your high horse, already and realize that maybe, because Bane had a book on him, he's just not all that
Bane's arguably the most powerful sith ever (force and saber, though I'd agree that he's currently #3 based on what we know), and he's only 27, has been studying the darkside for less than three years, half of that time from flawed teachings. He's quite easily going to surpass Sidious.