Want serious Mahjong? Try Akagi instead. Saki plays it fun and easy, preferring thunderous entertainment over logic, plausibility, and critical thinking. This FUNtastic underground gem needs more love. MAL already has plenty of lengthy reviews for Saki, so I'll keep this one to the point:
Pleasant Surprise #1:
For such a seemingly low-budget title, it's voiced by an all-star cast of seiyuu.
Pleasant Surprise #2:
Rather than play out as gagworthy as I expected, the hints of yuri actually spiced things up. Nothing is ever explicitly stated, everything is implied, and the light yuri factor whimsically floats in that fun stage before relationships get all dramatic and serious.
Pleasant Surprise #3:
The sheer number of characters with depth. Even some opponents come fleshed out with backstories, allowing us to understand, care for, and maybe even side with the opposition for a match or two.
Pleasant Surprise #4:
I entered Saki not knowing jack about Mahjong. I left Saki not knowing jack about Mahjong (except how one must exclaim a string of unrelated but awesome-sounding words as if spewing obscenities when revealing a good hand). Yet it still somehow managed to hold my interest so dearly!
Pleasant Surprise #5:
Again, for such a seemingly low-budget title, the visuals are bright, lively, and all-around surprisingly well done.
Pleasant Surprise #6:
The insane addiction. I don't really get addicted to anime very easily, but from the time I started to the time I finished, I simply could not get this show out of my mind. Mmmhh, one more episode...
Pleasant Surprise #7:
Yuuki. I usually hate watching characters that follow this silly and hyperactive archetype, but she actually synced well with the characters here. The only character I had a problem with was the only male in the main group, Kyoutarou, for being so uselessly flat and static. Everyone else: swell.
You know you love an anime when you get to the last episode dejected from having to leave that world, rather than feeling relieved from it.