Video Game Atlas
Via Joystiq, a very worthy site that's sure to stoke the fires of nostalgia. VGMaps.com is an altas for games old and new, with extremely impressive stitched together screenshot displays. Some of my personal favorites include Zebes, The Maniac Mansion, and the FFI Overworld.
Reminds me of the maps they use to have in Nintendo Power (early Nintendo Power, before they sucked).