I've seen some great posts here about the NHL playoffs, and they've definitely been great so far.
I've also been pleasantly surprised by the NBA playoffs so far this year. Usually in the NBA playoffs, things are so predictable - the favorite almost always wins, teams tend to win 2 or 3 titles in a row, etc. Okla City vs Dallas, Chicago vs Miami - pretty good final 4, with some great story lines. Also 4 teams that a lot of people wouldn't have expected to see here at the beginning of the year!