I've put maybe ten hours into Skyrim so far and I'm enjoying it immensely. However, I've completed my visit to High Hrothgar and want to diverge from the main quest for a while. I've been trekking around, marking places on my maps on my way to visit the various Holds of Skyrim -- and I'm a little disappointed. So far, they resemble each other immensely and I haven't been given any particularly captivating quests.
Does anyone have a suggestion for a truly awesome hold to visit or a really awesome quest-line for my mage-warrior to follow? I know there must be great content in the huge world, but right now I find myself skimming the too-similar surface.