As a box art fetishist, this might be the best website I've ever seen. It's called Box vs Box, and its purpose is to compare the box art of Japanese video games and their Western counterparts. Sometimes it's a straight Japan vs US matchup, other times it's a three-way royal rumble, with PAL games joining the fray (for those times when Europe and Australia got different art).
The site only started up last month but already has enough examples - most of them older games from the '80s and '90s -- to make you wish more publishers just let the Japanese do everyone's cover art.
Box vs Box [Tumblr]