I was recently added to a spammy Twitter list that I didn't want to be on and it's not the first time either. I guess is when you are added to Twitter lists it's always that little bit more exposure but if a list is annoying not aligned with your brand here is the way to get yourself off the list:
Click on the Twitter list that you’ve been listed on
Click on the username that created that list
Click BLOCK This will remove you from the list and block the USER.
However if you don't want to BLOCK the user then immediately.....Click UNBLOCK if you want to still follow the offender....but why would you?