I've had lots of much-loved favourite characters in fiction; Han Solo, Marvin the Paranoid Android, Lieutenant Commander Data, Captain Picard, Faramir, and Bigwig the Bunny to name but a few, but despite all of those fine characters, I' m going to have to go with Dean Winchester here.
In all my days of reading/watching fiction, I've never come across a character so complex and multi-dimensional. A combination of a brilliant idea, great writing, and great acting has turned Dean into a character that I truly, genuinely care very deeply about, to the degree that I have, on accasion, lain awake worrying about him!
Shrek once said that ogres have layers, but the average ogre is nothing compared to our Dean Winchester.
The character is brilliantly conceived with a great backstory; traumatised by tragedy, blindly idolising an overbearing parent, and devoted to his brother to a completely obsessive degree. (The brothers' co-dependence is for another discussion, but deserves an honorable mention here). On top of all that, he harbours a crippling (and totally undeserved) inferiority complex, all tied up with a reckless desire to do the right thing.
I once wrote a drabble in which I said that a suit of armour isn't always made of metal, In it, I wrote that Dean's armour is composed of:
His aggressively spiked hair;
A massive jacket that broadens his silhouette and hides him from hostile eyes;
His great heavy boots that make him look an inch taller and sound ten pounds heavier;
His strutting cowboy swagger and his badass smirk;
His 'couldn't give a crap' attitude;
And finally, his smart mouth with its talent for causing maximum offence in minimum time.
But inside that armour is a vulnerability and insecurity that is quite overwhelming (I've said it before, for a badass tough guy, Dean doesn't half seem to cry a lot!) He's unbearably lonely and afraid - not for himself, but for Sammy; maybe even for Castiel. It just makes you want to hug him and never let go.
Added to this are other factors like his subtly underplayed intelligence, his resourcefulness and quick wit, his roguish charm (love 'em and leave 'em), his unswerving loyalty, and his undeniable courage.
But he's not Mister Perfect, and that's another reason why he's such a believable and endearing character. He's deeply flawed and with the life he's been forced into, it's hardly surprising. He's impetuous and impulsive, very often bull-headedly stubborn, he is crippled with self-doubt and self-loathing and appears to be the only person that can't see or appreciate his many qualities (heck, even Crowley can recognise those). Unfortunately, I believe he tried for so long to be his father, I really don't think he actually knows who Dean Winchester is, and that's heartbreaking.
In Dean's life, the only character who has never once let him down, abandoned him or hurt him is his car - no wonder he loves her so much.
And as if that's not enough, all that turmoil is wrapped up in a drop-dead handsome package that takes your breath away.
So, there you are - have I gushed enough?