I spend ages nicknaming and I never think it's quite right, but after a while spent with those nicknames they just become the pokémon.
At the moment on White I've got:
Archeops: Quezacoatl - A shortened version of the name Quetzalcoatl, the mythical feathered serpent.
Zoroark: DarkNation - The name of Rufus Shinra's pet dog/panther thing.
Scyther: Antlion - Always looking to change this one. Taken because it looks similar to the HL2 antlions.
Scraggy: Carcer - The name of a ruthless criminal from one of the Discworld novels. Chosen for the Dark/Fighting combination.
Serperior: Anacondaur - A random battle enemy in FF8. Might rename it, might not.
Cofagrigus: Soulstone - Chosen because of the Ghost type and the small stone idol of a face on its pre-evolved form.
Zebstrika: Ixion - The name of the thunder elemental aeon from FFX.
Throh: Titan - Stuck for something good here so I just went with whatever.
Klink: MetalGear - Pretty much.
And in the early stages of the game I had a Pidove called Sky Rat.