Namco X Capcom for PS2 is relatively playable but not horrifically fun. Osu! Tatakae! Ouendan! and Ouendan 2 for DS are awesome rhythm games and while they have text, there's also pictures so they're easy to understand. Apparently there was a PS2 remake of NiGHTS that I wanted to get when I was in Japan but I couldn't track it down anywhere. Then there's versions of games that came out here but got extra editions in Japanese, such as most of the PS2 Final Fantasy games, of which the international versions have English voice acting but Japanese menus.
Tales games, in my opinion, can still be relatively fun in Japanese because the combat is so fun, so that gives Tales of Rebirth, Tales of Destiny 2, Tales of Destiny Remake, Tales of Phantasia X and PS3 Tales of Vesperia and probably more as possible purchases, but you'll need a story guide to understand them.