Been watching Saki lately. This is one of the weirdest anime i've seen in years. As you can see from the thumbnail picture, the anime is full of Moe characters with lots of seiyu, just like normal.
However, what makes this anime a bit different is that those girls play Mahjong games, and the story goes like some Jump comic manga (a la Dragon Ball or Kinniku Man): battle with unique characters with their own background story, every week.
Not something I could recommend to everyone, but seems very popular in 2ch :)