Who o what is the most powerful supernatural creature San and Dean have encountered so far?

its gotta be the trickster, he's a demi god! prolly better than ángeles cuz he could just trick em idk thats a tough one sayin there better than ángeles but might actually be. so trickster!

Lilith o Y.E.D o even Meg but I'd say Liltih

I have to go with the archangel Zachariah. Castiel called them 'God's most fearsome warriors', and they'd have to pack some kind of celestial puñetazo, ponche to be called that! Since they've already established that Sam and Dean's destinies must be allowed to play out, we likely won't see just what he is capable of for a while. He will not interfere...yet.

(btw, this probably should have been a pick because it's an "opinion" question, ;) )

lillth,y.e.d o the ángel because the ángel can send dean staight back to hell

deffo lilith

Sam and Dean thier most powerful creature they have run into is Angels. The only thing that can kill an ángel is another ángel probably GOD too but I'm not sure.

i would have to say the yellow eyed demom

i would say the yellow eyed demon. he killed the boys mother, and then sams girlfriend. he is the reason they started to hunt, just like their dad.

My vote is for Jamie(a boy born from a demonic bloodline). Although it is clear that Death(The Horseman i mean) is the strongest.

It has to be God!Castiel, even though we've only seen one scene of him yet. Apart from that I would say the Archangels o Death.

This guy right here:

Leviathan, they are freaking powerful!!

Bloomin Castiel - Just can't get rid o the beggar!!!!! ;-)

Of course the real answer is the wonderful Death - he out lives everything! Oh Hail the Mighty Death (bowing lowly) !!!

Lilith, Yellow Eyed Demon, Dick...

Lucifer.

he's the freakin' devil!

I'm not going to give tu just one but two most powerful beings and they are God and Death.

They met Zues who is a god and immortal, they also met Lilith created por god and is also immortal but both were killed a bit far fetched on the shows part lol.