What would be the least casual, acceptable dress for men going to a Broadway show? 
Nowadays, you can get away with wearing just about anything to the theater. There is no dress code per se. But since you asked us...
Bare minimum? Khakis and a clean shirt. No sneakers, no jeans, no logo tee-shirts. This goes for the ladies, too.
You could spice it up a little. Collared shirt, nice shoes. A tie if you feel so inclined, but that's not really necessary. And this may be the girly side of Ask Gothamist speaking, but why go the bare minimum? Why not use a trip to the theater as an excuse to get a little dressed up for a change? Show your date how well you clean up?
But we know, we know. If you're going to sit for three hours, you might as well be comfortable, right? You can't go wrong in khakis and a decent shirt.




With the prices these days on Broadway, who can even afford khakis?
Yes, I saw some dudes going to see The Producers in gunny sacks.
But what's always cute is how the kids from out of town (I'm talking about NJ or Long Island suburban kids, on field trips) are super dressed up for a night on the town, which includes dinner at Beefsteak Charlie's.
Actually, what got me is that when I took an out-of-town friend to a show a few weeks ago, I saw a group of girls who were all dressed identically. Pastel polo shirts with the collars upturned paired with coordinated floral miniskirts.
Bah, I'll wear jeans to anything, including your wedding.
um, is it just us, or did the questioner actually ask what is the *most* formal attire appropriate for the theater? Not to get all eats shoots and leaves on your ass, but he wrote: "the least casual, acceptable dress" and least casual means least casual....
Hmm, I guess we have to adjust our reading glasses. Wear a tux, then! I don't think it's possible to overdress for a show.
The theatre-lover in me agrees: dress respectfully when you're going to see a show, especially a Broadway show. But I don't always follow that rule. I grew up out-of-town, and a trip to NYC meant getting on an early AM bus and leaving on the same bus that night. In between, seeing a Broadway show was just one of the things on my sightseeing schedule, which had me traipsing all over the city, and that mandated comfy shoes at the very least. Now I live in the city, but even so, if I can score last-minute tix to something I won't turn them down just because I don't have time to go home and change. So I say, yes, dress nicely, especially if it's a date -- but don't look down on those who don't. Sometimes the people in track suits and cross-trainers are much more enthusiastic audience members than the bored corporate suits.