I've shopped from Ozgameshop before.
Great prices, delivery takes a little long though (they're based in the UK)
I'd also suggest Buy Video Games for Consoles and PC - From Japan, Korea and other Regions - Play-Asia.com
Not all that cheap, but they have a lot of Japanese games that aren't released in the West. They tell you in the write-ups whether it works on PAL or NTSC or if it's region free.