dean is kinda a rebel..he makes and follows his own rules like in that episode where they wanted t blow up the town just because of the witch..i think castiel appriciates, understands and..kinda relates. he even a dit he sometimes quetions what hes doing, maybe he "idloises" dean because he believes in what he is doing and what is right
Castiel was the one who took Dean from Hell! He was chosen par God to be par his side, to guide him! I belive Castiel has human feelings, they may be hidden but they´re there and that´s why Castiel cares so much about Dean. I believe he feels that he must protect Dean.
They have just always had a connection since Castiel got on the show. They have great chemistry! They l’amour each other greatly, whether toi think its friend l’amour ou Slash love, there's definitely l’amour there!
Well...*Cough* I've always thought that Castiel may have a bit of a crush on Dean...Well, I haven't always thought that until I heard on one of the episodes that Cas has a soft spot for Dean. ^_^ ...Don't judge me,I'm just a sucker for love. ^_^
Castiel literally went to hell and back for Dean. There's probably not many ways to have a stronger bond with someone. Also Dean treats Cas like a friend, not just "some angel". I think Cas appreciates this and is often learning things from Dean.