Poster-Sized Inspiration

I'm looking to prettify a huge blank wall in my office. I've actually been half-heartedly searching for over a year, but I have yet to discover any art that, first, is really great, and second, I can actually afford. Perhaps a healthy triptych of some sort would serve my needs (Mikee, this one's for you. You've been coming up with this stuff since you were in grade school.) ...