My characters tend to be loyal (sometimes to the point of fanaticism or stupidity) to ideas or causes, but there are very few who tend towards loyalty to *people*, and those come over as refreshingly anarchic, I have been told.
Loyalty is such a nicely complicated thing that my leviathan of a political intrigue story (the one that always demand a complete re-write just when I think I'm nearly done) lives solely on clashing loyalties and duties. Be loyal to your friend or to your friend's cause? To your boss or to the ideas he claims to stand for? The people in the story have a saying, "Loyalty's a sword with a poisoned hilt".