Sadly, I agree. When I watched Jared play Lucifer, all I saw was Sam in his expressions and his voice. Pellegrino can keep the mantle of SPN!Lucifer. ;)

Aw, I enjoy Dean/Cas, but I don't bother writing it because when I need it there are tens of other authors who'll give me a fix. :p Sam/Gabriel would have overcome a lot of initial h/c for the reasons you cited; people also put a lot of faith in Gabriel's humour to overcome any situation and Sam's bitchface.

But I can find a way to love every combination if I consider it long enough to find a way!!! :D I just love some more than others (read: angels, angels, everywhere).