Oxymoron (pl. oxymora): an expression that contains two normally contradictory terms
Popular examples of oxymora include "mandatory option", "freezer burn", tight slacks" or "military intelligence" - the latter being an opinion oxymoron (an expression that may be or not be an oxymoron depending on your opinions).
It's interesting though, that "Microsoft Works" is not listed as "opinion" oxymoron, so I guess everybody agreed on that one...
Here's an illustration for "opinion oxymoron":
Indeed, as many times as I heard "That's a one-man job" - it never came from a guy. Maybe men just like to be efficient, so they delegate things. (Even when my son is taking out garbage, he volunteers me to help him.)
...I've almost become an oxymoron expert by now: such is our life, that should we ever come to terms, the terms are normally contradictory...