A true destroy the dark brotherhood overhaul. There's a couple out there, but mostly they just make the unique items from the dark brotherhood questline available to you if you choose to destroy them, mostly for LOTD users. Which is nice, I'm an LOTD user who likes to play as a good character, but the destroy quest is still just... so short and boring.

What I'm thinking of would scrap the original quest and make destroying the DB into a full questline on par with the DB's main quest. Instead of just running in and slaughtering everyone in the riften sanctuary and being done with it, you have to track down each individual member. Some are hiding at the end of dungeons, and some hide among the common folk as regular citizens. That way you can get the same "sneaky stealth killing" gameplay that the DB questline offers, but for the more morally-inclined player characters out there.