I realize this question is contrived, but I figure it might provoke some fun discussion, so here goes:
If you could push a button and have your brain modified to precisely remove a cognitive bias (and have no other unnecessary effects—most convenient possible world), which would you choose? Why?
What if you were choosing for the whole human race?
Not sure if this is a bias or not, but "magical thinking" -- the mode of thinking that implicitly ascribes a hidden 'essence' to events or objects. Different manifestations of this are: karma, homeopathy, "handmade is better than factory made", and so on.