I once ran a campaign where there were no "sub-races" of Elves...only the one race, "Elf", who were Lawful Evil.
They were the big super-powerful, decadent imperial force on the campaign world, with slaves, etc. They basically viewed themselves as the pinnacle of creation. Their cosmological view was basically like this:
GODS---->ANGELS (DEMIGODS, ETC.)----->ELVES------>OTHER RACES----->ANIMALS
They viewed all other races in a similar vein to the way we view primates...animals who are smart, but still animals. In fact, Elves had been known to EAT other races in some regions (in the same way that some human cultures eat monkey).
Think of an entire species comprised of Galadriel when she freaked out momentarily in FOTR.