I seriously hate motivational posters; we had a couple in the lobby when I was at PNL.
They're all, like, a basket of kittens or a sunset over a canyon with some half-baked misquote of self affirming mung in that characteristic corporate type face - I always preferred the alternative versions from www.despair.com and the ones in the Photoshop Phridays at Something Awful.
However, check these out: Marvel Superhero Motivational Posters.
Arguably, the coolest being - Magneto - Possibilities
“Within me lies infinite power... before me, endless possibilities... Decisions... Decisions... Decisions.”
Though perhaps, instead - Magneto - Possibilities
"Nature has made us superior! We are the living future of this mighty planet, this world is our world now, take it! It has begun!"- would be better. It's probably a good thing I'm not still self-employed…