I found a link to et tu Gamer? in the comments to a Gamasutra article about game preservation. Right away I saw that this was without a doubt a site worth bookmarking. The homepage features galleries for a select few games but the gallery section contains a comprehensive archive.
Apparently the creator is attempting to archive as much video game art as he can get ahold of. The I’ve seen so far is incredible quality and definitely worth a gander.
Check it out!