Sleepy angels were the best types of angels. Dean had decided this long ago, the first time he saw Castiel asleep. The first time they slept in the same bed, the angel had his usually-concealed wings out and was twitching them slightly in his sleep. Even if it was a sign of ill health, it was still the most amusing thing Dean had ever seen. And, while he detested calling things adorable, he'd make an exception for a drowsy, twitchy Cas. Especially if that drowsy, twitchy Cas was snuggled up in his arms.
Part of the reason Dean loved Cas was that he was always so cuddly. The hunter would wake up on a motel bed with the angel resting his head on his chest or curled up by his legs. He occasionally insisted on snuggling with Dean when he was driving, in which case Sam would be ordered to take the wheel. The younger man always seemed less than thrilled at these rides. Dean never cared a bit. Not that he noticed.
No-one had given Dean so much love before, and it honestly warmed his heart even when nothing else could. In a world where almost everyone was against him, having one of the most powerful, wonderful people he knew find him so brilliant and amazing was almost unbelievable. He really did need someone like that, more than anything. Even if he never meant as much to Cas as Cas meant to him, it didn't matter. But something in the way that Cas threw himself into the line of fire for Dean, how he cared about him as if he'd known him all his life, the way he always knew what to say... he knew he did matter to the angel. There was nobody more important in Castiel's mind.