Based on all the comments you've made about you and your husband's past and projected future theater experience, I'd recommend Phantom of the Opera. It's certainly a great crowd pleaser...and there must good reasons why it'll probably pass Cats as the longest running musical in Broadway history.
Is the the best show on Broadway? I don't think so. But, it's definitely entertaining and is the one I'd recommend in your situation.

Hi Charblack - go to Playbill.com and click on "Upcoming Broadway Shows." Lots of new stuff coming in, including a revival of La Cage, a musical version of Little Women, a musical version of Dirty Rotten Scoundrels and more. Once these shows start previews you'll be able to get some feedback on them.
Meanwhile, Kristin Chenowith has left Wicked - I have not yet heard anything about her replacement.

Based on how you discribe your husband (if I'm reading you correctly) I'm not sure PHANTOM is the show your looking for. Special effects are good, but the music is...well...operatic. He probably won't come out of the theater humming tunes. Someone who doesn't like theater I think may have a hard time with this play.

Depending on his sense of humor AVENUE Q or HAIRSPRAY might be a good choice. I'll stand by my previous recommendation of WICKED.

Don't get too concerned about cast changes. On any given night an actor you wanted to see may not perform. FWIW I saw WICKED after Ms. Chenowith and Joel Grey left and still enjoyed the play very much. Jennifer Laura Thompson playing Glinda (the Chenowith role) was great. I believe clever writing is what made the show.

I don't mean to start a debate, but to brush off Phantom of the Opera as "operatic" is almost laughable. It is probably the most popular musical in history, having been seen by millions throughout the world. If anything, it is very mainstream!
Hairspray and Avenue Q are indeed outstanding shows. But, for the infrequent/inexperienced theatergoer, neither are what I would recommend for their one and only NYC Broadway experience.
I would have also recommended 42nd Street, but that show is closing in a few months.

I agree with Howard about Phantom. And I never see it without humming the "Masquerade" or music box theme for days.
In May I had the pleasure of seeing it once again, this time in London from a first row mezzanine seat and it still comes out a winner every time.
While I loved Wicked, it really doesn't seem like it is for everyone. Why was I the only one who laughed aloud at the "traveling in a bubble" joke and many of the others?