I was up in NYC at the end of June and caught two celebrity-filled Broadway shows: Hedwig and the Angry Inch and the Cripple of Inishmaan.
Hedwig was easily the most fun I've ever had a musical (technically a rock opera). Neil Patrick Harris was superb. Hedwig's backing band also was fantastic in a rock and roll way, not a 'talented Broadway musician' type way. This made a lot more sense once I read their bios: they include former members of the Antlers, the Wallflowers, and Morningwood. Even the understudy for Hedwig's love Yitzhak is the lead singer of popular Led Zeppelin tribute band Lez Zeppelin (they play the State Theatre all the time but I've never seen them).
Daniel Radcliffe, aka Harry Potter, starred in the Cripple of Inishmaan, a dark comedy by my favorite playright Martin McDonough (The Pillowman being my favorite of his work, though I've never seen anything by him that wasn't awesome. Radcliffe was great, but was easily the sixth or seventh best actor in the play -- that's how good everyone else was.