One of the more interesting LOST posters I've purchased is entitled Unstuck and was created by an artist who goes by the moniker DrMikey.
Taken simply as a portait of Desmond Hume this is already a very cool piece of art; however, there is some amazing detail in the piece which elevates it to an even higher level.
On careful inspection one can see that Desmond's hair and some of his facial features are composed of words, words spoken by Desmond during the course of the series.
Of course Desmond's tagline, "I'll see you in another life, brother" is included as are various references to Penny and Desmond's admonition to Daniel Faraday -- "I know about Eloise."
I haven't yet gone through and tried to decipher every phrase on the print, but I'm sure somewhere in the blogosphere a fan has already done so!
In my opinion, the concept and execution on this piece ranks it in the top tier of all LOST prints.
The front of the poster contains only DrMikey's sig, whereas...
...the back of the poster includes the print number, which in my case is #31 of 100.
Copies of this print are still available on DrMikey's site, so if you are as coolified as I am about it be sure to pick one up. DrMikey has a few other great LOST prints as well featuring Richard Alpert, Flocke, and the Black Rock.