I've just got back into Skyrim and I've been riding through the Main Quest (Imperial style) to learn the story.

I just bought a house in my favourite city, Riften.
I am now just doing some quests that I had picked up along my travels but I would like to know what to do now. (Any quests that are AGAINST the Dark Brotherhood?)

Troll much?

You can do bards college, winterhold, dragon priest masks, world walls, treasure maps, ...

Yes, there is an actual quest to kill off the entire Dark Brotherhood. But, it is somewhat of a spoiler to tell you how to start it off. If you haven't figured it out yet by coincidence, then you can always check out how to start that particular quest by googling it (however, it kind of stinks to find it out this way... much better to 'discover' it).

No? I don't think so..

And thanks. I was just wandering if there was a quest line... Now to go discover it

He he, it was just something about your avatar and signature
But, on the serious side, you could do just about everything in this splendid game:)
And as a member of the Dark Brotherhood i can assure you that as long as you kill people,
you are in the safe zone;)

Ohhh right. I'm a hardcoe Fallout fan and always will be, doesn't mean I hate TES though

The temptation to find out the 'trigger' is pretty great... I admittedly did this myself and I slapped my forehead when I did it (because I was soooo close to hitting the trigger at one point and actually ignored it). If you do look for the trigger online, just to warn you in advance, there are two triggers... one to put you in direct contact with the Dark Brotherhood followed by another one. I won't give you any clues because it's much, much better to 'discover' this stuff for yourself... there is a definite cool factor. I'm warning you that if you give into the tempation, stop reading when you find out what the first 'trigger' is so you'll at least experience the cool factor of the second trigger.

Haha ok.