Pale Fire is brilliant - wonderfully written and very funny. The poem itself is pretty good too - one of my favourite bits:

How to locate in blackness, with a gasp,

Terra the Fair, an orbicle of jasp.

How to keep sane in spiral types of space.

Precautions to be taken in the case

Of freak reincarnation: what to do

On suddenly discovering that you

Are now a young and vulnerable toad

Plump in the middle of a busy road