Good news for expat gamers – Playstation 3 games are entirely region free. The console’s menu screens can also be set to English, and many PSN games have an English option. Unfortunately, DVDs and PS1 & PS2 games are region locked (with the occasional exception on PSN).
As for the games you can buy in Japan:
Japanese version has English option:
Assassin’s Creed II
Battlefield 1943
Battlefield: Bad Company
Bionic Commando Rearmed
Bioshock 2
Biohazard 5
Blazblue: Calamity Trigger
Bomberman Ultra
Burnout Paradise: The Ultimate Box
Dark Kingdom
Dark Sector
Def Jam Icon
Devil May Cry 4
Eye of Judgement (although cards are in Japanese, thanks Christopher!)
Far Cry 2
Fight Night Round 3
Gundam: Target in Sight
Killzone 2
Little Big Planet
Lost Planet
Lumines Supernova
Medal of Honour Airbourne
Metal Gear Online
Mobile Suit Gundam: Target in Sight
Ninja Gaiden Sigma
Pixeljunk Eden
Pixeljunk Monsters
Pixeljunk Monsters Encore
Power Smash 3
Prince of Persia
Race Driver Grid
Ratchet and Clank – Quest for Booty
Ratchet and Clank – Tools of Destruction
Resistance Fall of Man
Resistance 2
Ridge Racer 7 (also supports other languages)
Rise from Lair / Lair
Saints Row 2
SOCOM: Navy Seals Confrontation
Sonic the Hedgehog
Soul Calibur 4
Tekken 6
Tomb Raider: Underworld
Uncharted: Drake’s Fortune (Japanese version is partially censored)
Uncharted 2
Unreal Tournament 3
Untold Legends: Dark Kingdom
Virtua Fighter 5
Warhawk
Winning Eleven 2008
Winning Eleven 2009
Wipeout HD
WWE: Legends of Wrestlemania
Japanese version lacks full English:
Afrika
Aquanauts Holiday
Armoured Core: For Answer
Assasin’s Creed
Bioshock
Brain Challenge
Burnout Paradise
Call of Duty 4
Dragon Ball Z
Enchant Arm
Eternal Sonata / Trusty Bell
Everybody’s Golf 5
FIFA 2009
Formula 1 Championship Edition
Genji: Days of the Blade
Guitar Hero 3 (The training is in Japanese, but most of the game is English)
Gundam: Musou
Gran Turismo 5 Prologue
Heavenly Sword
Imabikisou
Intial D: Extreme Stage
Lego Star Wars: The Complete Saga
Mahjong Kakutou Club / Mahjong Fight Club
Mahjong Taikai IV
Metal Gear Solid 4
Mirrors Edge
Miyasato Miyoshi Kyoudai Naizou: Sega Golf Club
Motorstorm
NBA Live 2008
Need for Speed Carbon
Need for Speed Pro Street
Railfan
Record of Agarest War
Rise from Lair (Lair)
Shin Sengoku Musou 5
Shirokishi Monogatari
Star Wars: The Force Unleashed
Stuntman: Ignition
The Elder Scrolls IV: Oblivion
The Godfather (English audio)
The Last Guy
Motorstorm: The Japanese version doesn`t support online battles.
PSP
The PSP is also region free for games.
Games where the Japanese version has an English option:
Final Fantasy Anniversary Edition
Final Fantasy II Anniversary Edition