I have a Troll Hunter. He's one of my favorite characters. Back before The Burning Crusade, whenever the Ancient Petrified Leaf dropped off the Cache of the Firelord in Molten Core, I would pass on it so that it could be given to other Hunters in the raid even though I was in line for it. I wasn't being generous... I just hated bows. In my opinion, they made utterly boring sounds when fired. I preferred guns. I loved the bang of shots and autoshots. That was fun for me. I mean, I wanted the Gurubashi Dwarf Destroyer because it looked cool.
I know what you're thinking. I was a troll passing over a bow. Well, I didn't care for (what was then) +5 weapon skill. I liked guns. Even now that Bow Specialization grants 1% crit, I still prefer guns. That was just the way I want to play and I'd usually pass on all ranged weapon loot unless it's a firearm. This Troll Hunter of mine also has white hair and as a rule, only tames white pets. My stable includes the white bat Ressan the Needler, the white cat Sian-Rotam, and the white spider Leech Widow. The day Blizzard makes Aluntir, the white Silithid wasp, a tameable exotic pet is the day I spec Beast Mastery.
I like min/maxing as much as the next guy, really. But there are just certain idiosyncrasies with the way I play, such as my Shaman who pursued Goblin Engineering for the Pet Bombling. He's all about Engineering, so when Wrath comes he's likely to be on his motorcycle when on land and on his flying machine when in the Outlands or Northrend. Oh, he's got white hair, too, just like my Hunter and Paladin. It's just one of those things. I'm sure you also have little quirks on your characters or the way you play. What are your WoW idiosyncrasies?