I haven't played in years, so I can't remember, mostly just some old famicom/nes games and a few Japanese websites,
Tenhou was really good, but it's all in Japanese, there's tons of translation guides if you just look up like "Tenhou mahjong guide" or something.
Also, the Yakuza games on ps3/4 have mahjong in them in addition to being all around fun games.