Out of all the major quest-lines in the world of Skyrim, which story was actually decent enough to get you hooked?

My current character is a Redguard nightblade, using every magicka school (except destruction) along with archery, and onehanded (bound bow/dagger/bow) along with sneak. I'm having a blast playing through the Thieves Guild quests and side quests, earning my riches stealing crap from rich people and helping Karliah and Brynjolf resurrect the Nightingales. Definitely my favorite guild. But I'll have to say, Dawnguard was an epic set of quests, travelling to morbid and breathtaking locations like the Soul Cairne and the Forgotten Vale. I'm going with Dawnguard.

The Bard's College. Such depth.

In all seriousness, they're all pretty bad IMO.

Out of those, I prefer the CW. Even though it can be a bit buggy.