chimpanzee is in, monkey is out
pistachio is in, peanut is out
turkey is in, chicken is out
pumpkin is in, but the pie is out
cacophony is in, harmony is out
stress is in, relaxation is out
variety is in, tedium is out
operetta is in, symphonies are out
hospital is in, but the doctor, nurse and patient are out
roommate and companion are in, but friends and family are out
insecticide is in, but all manner of creepy-crawly things are out, including ants, spiders, bees, bugs, etc. Even centipedes are out, though you may expect them to be in...
The 0, 1, 2, 720! Puzzler