The Thirty-Six Lessons of Vivec tops a lot of people's lists, in an "esoteric religious text" sort of way. Good luck understanding it, but it feels unique and interesting at least.
The Firsthold Revolt has some fun plotting by an old favourite of mine from Daggerfall, Princess Morgiah, and
A Game at Dinner for some equally nice plotting by her brother Helseth.
There's an awful lot more, of course. Pick one up at random and chances are it'll be good.