Here are two words I am going to try not to use anymore:
1. Pig (or ape or shark or any other animal name) as a derogatory term. Pigs are fine animals. But even if they weren't, who are we to judge them? Better to call a poorly-behaved pig a human; except there's really no such thing as poor behavior in pigs, just behavior that is less convenient for those trying to imprison and kill them. And that is, actually, good behavior.
2. Nonbeliever or unbeliever for atheist. Even "atheist" has a negative prefix, which gives the impression of absence and nihilism. This built-in absence makes it easy for theists to claim "they have no morals, no conscience, nothing to aspire to"--when in fact we believe in a great many things, including reason, imagination, progress, beauty, wonder, brilliance, mystery, and even the sacred. The fact that there are no good alternatives for "atheist" shows the extent to which theists have controlled our language. I do not, however, find much power in the term "Bright" as proposed by Dawkins and Dennett. (It does have the advantage of being every bit as smug as "believer" or "Godly" is for others.) I'm a believer, but not in God.