Candide

I suspect there's something to be said about a book that hasn't lost any of its relevance for over 250 years. It's been probably 15-ish years since I first read Candide, and it's been my yardstick for every satirical novel I've read since. It has a time and a place, but it transcends both somehow, and you don't need to know the history around it to know the ideas it viciously assaults–though knowing the history makes it that much more fun.