Around 71 hours in, level 22 with my first character, a Khajiit Adventurer/Spellsword. So far I've only done a few MQs and the first few Companions Quests. I'm taking my time to savor the land and all it has to offer.
I'll be saving the Thieves Guild for my Thief character, the College for my evil Mage, and the Civil War for my Nord. I'm not sure who is going to tackle the Dark Brotherhood yet.
I expect hundreds of hours in Skyrim, but over time.