For example, I'd love to wear a leather eyepatch on my death knight, but since he's a plate wearer? No go. I would pretty much wear an Ashkandi forever and ever if I could, but if I pick up a two-handed axe in a raid or instance? Can't transmog it. My hunter has it even worse. I roleplay her as more of a backwoods, live-off-the-land type turned sniper, so she'd be more likely to dress in brown or black leathers instead of big, flashy suits of mail armor. Alas, under the current rules of transmogrification, I'm stuck with tier 11 while her Defias Leathers stay languishing in the bank. Finally, I had every intention of dressing up both my blood elf paladin and my gnomish warrior in level 60 PvP gear, but you probably heard that only those characters with the old high-level titles get to transmogrify that stuff for now.
So what about you? Are some of the transmogrification rules keeping you from putting together the look of your dreams?