Image courtesy Metroid Database

Metroid: Other M certainly had some delicious artwork, most of which was only available in Japanese, but those hard-working folks at the Metroid Database have translated plenty of concept art into English.

From sketches of Zero Suit Samus to maps and boss concepts, the artwork is well worth a look over if you're into Samus's most recent adventure. Be warned though: the artwork and accompanying notes contain spoilers, so if you've not finished the game yet then you may want to wait until Adam authorises use of this artwork.