My first one I found was a Easter egg containing a Robert Frost reference. He is a very famous poet if you have never heard of him. I'm a big fan of his which is why it's my favorite Easter egg.
You go to riften and head in to the bee and the barb. Once you're there there'll be a guy there that wants a horse named "Frost" which starts the promises to keep quest, which is a line from the poem "stopping by the woods on a snowy evening". After that you go to the black briar house through a bit of woods which refers to the line "whose woods these are". More Easter eggs to come!
