Right up there with military intelligence

Some favorite Oxymorons

assistant supervisor
new tradition
original copy
plastic glass
uninvited guest
highly depressed
live recording
authentic reproduction
partial cease-fire
limited lifetime guarantee
elevated subway
dry lake
true replica
forward lateral
standard options
mandatory volunteer
mutual differences
nondairy creamer
open secret
resident alien
silent alarm
sports sedan
wireless cable
mercy killing
lethal assistance (Contra aid)
business ethics
friendly fire
genuine veneer
full-time day care
death benefits
holy war