Forgive me if this suggestion is widely known. I hadn't seen my particular crash or this solution in any of my searches.

My crash was happening when I tried to enter the archmage's quarters where I would meet Quaranir for the first time.

The solution went like this. I went into Steam and:
1. Went into Library
2. Right-clicked on Skyrim and selected Properties
3. Selected LOCAL FILES tab
4. Clicked on VERIFY INTEGRITY OF GAME CACHE...

After a few minutes it reported a problem with one of my files and reacquired it. The file was over a gigabyte in size, so this might not be snappy, but it worked for me.