It started out as a most powerful HERO thread, Doomsday is a definate villian and Spectre is on the line. If it were to be the most Powerful in the whole DC universe than Spectre would take the cake.

Nope.You need to check out Action Comics Annual 1991#3 which is an Armageddon 2001 title.In it Superman becomes president.Guy Gardner doesn't like it and attacks Supes WITH his power ring.Guess what happens?Of coarse,even after I tell you I know those of you who can't be reasonable are gonna say blah,blah,blah.Anyway,the first blast from his ring knocked Supes on his tail.That was only cause he was surprised.After he got up,it was all Superman.Gardner zaps Supes again,and Supes just walks right up to Guy even though Guy has had a continuous big green beam(or whatever you wanna call it) on Supes at full blast,and Supes just put his fist around Guy's fist,including the ring and simply takes it off.Talk about easy!!You said"any of them would kill supes if they wanted to" that's total H.S.! On the other hand,Supes,if HE WANTED TO COULD KILL ANY GREEN LANTERN and just about anyone else he wanted to!The only Lantern that might be able to give Superman a run for his money is Hal Jordan.And from what I've heard he's not around anymore.

Batman is still the most powerful.

What he lacks in physical strength he MORE than makes up for in intelligence, cunning, and planning.

He KNOWS the Who's Who of the ENTIRE DC Universe. Even the dead ones (because nobody stays dead in comics). He has plans within plans within plans to "take care of" any hero/villain that steps too far out of line and needs to be taken down permanently.

Now I know Batman will NEVER take a life intentionally but he has no qualms about putting someone in statis/lock-up indefinitely. And if Batman puts someone in lock-up the lock-up WILL BE secure and unbreak outable (I don't think that is a word, but you get the idea).

And I know the naysayers will come back with:

"but (insert name here) will swoop down at super speed and kill/render inert/knock out Batman before he knows what is going on."

Sorry, NO they won't.

Batman is only caught unawares if he wants to be caught unawares.

Batman is akin to Santa Claus. The man knows who's been bad or good. He knows what is going on in the world at all times.