Most, if not all, the games I enjoy the most are the Japanese ones.
IMHO, Japanese games have better storylines, better character designs, better music, better replay value, better graphic designs... just downright better than any American game I have played, with few exceptions like GoW, GTA, The Curse of Monkey Island, etc.
Here are some great Japanese game titles/franchises:
Metal Gear Solid, Resident Evil, Legend of Zelda, Super Mario, Chrono Trigger, Chrono Cross, Final Fantasy, Tales of Eternia, Legend of Dragoon, Bushido Blade, Tekken, Street Fighter, ICO, Shadow of The Colossus, Sonic The Hedgehog, Star Ocean, Dragon Quest, Metroid, Devil May Cry, Silent Hill, Kingdom Hearts, Castlevania, Xenogears, Vagrant Story, Pokemon, Mega Man, Okami