In the past I've posted the awesome charts, made by DeviantART user DirkLoechel, that compare the size of fictional spacecraft from a wide number of sources- such as the popular movies Star Wars & Star Trek, and video games such as Starcraft & one of my favorite games, Mass Effect.
On Gizmodo, I saw (what he claims to be) the last update to this awe-inspiring collection of fictional space vehicles. They include ships of mind-boggling size, up to 24,000 meters, or almost 15 miles long! The beauty of building in space is that there really is no size limitation due to gravity fields or restrictions on the area that a vessel can take up.
(click for larger image)