I'd list a bunch, but I ain't takin the fun away here. So, go ahead and make some up.

But for starters:
Collect the yaku (Scoring all the yaku at least once lifetime)
First Yakuman
Joke hand (Nagashi mangan)
Centurian (Scoring a +/- of over 100)
Bury the hatchet (Winning a game while putting someone into the negatives)
POW (Winning a hand using the Pao Rule)
And so on.