I don’t often pay attention to motivational posters, but the pithy Mark Twain ones at Izismine.com are cool. As far as I know these are all actual Twain quotes.
I don’t know what it takes to be remembered for hundreds of years for saying the most backhanded things in your century, but it’s definitely a distinction I would fight for. Although I think his sly remarks are slightly enhanced by the fact that he was also an amazing novelist, so I think I have some work cut out for me.