Okay, I had a quick look at what’s playing on Broadway in December, and I’ll definitely second @iamthemob‘s suggestion of In The Heights and @deni‘s suggestion of Fela!.
If you’re not into traditional musical theatre, what are you into? At the one end is The Phantom of the Opera, at the other is American Idiot. I’m not sure if your wife would enjoy that second one (but if she likes that sound, you could also see Bloody Bloody Andrew Jackson)
If you go see Jersey Boys at least you’ll know the songs. Then again, it is a jukebox musical, so your wife may not be so interested.
You could also look up La Cage Aux Folles. I’m not sure if it’s to your tastes, but it is insanely funny and very entertaining.
There’s also Next to Normal, which I don’t like, but is still very popular. It occasionally sounds like musical theatre, but there are no jazz hands in sight. If your wife knows anything about contemporary musicals, she would have heard of it. Is this a surprise present, or can you involve her in the decision?
One final suggestion from me: The Lion King. I’ve never been to see it because Disney musicals are more expensive than others, but it’s a great show.