Bring wine. Don’t bring glasses. Suck it up. It’s just one night.
Phil Jones
when I host a big crowd I’m bout to run out so BYOG prevails
Turn it into an educational opportunity. Bring your glasses and have them taste out of both so they can experience the difference good stemware can make.
Isn’t it wonderful when a clear WB consensus emerges!
How about this?
Since you know they’re into food, and asked for nice wine: Start a conversation before the dinner (early that day, or the day before). Ask what they’re thinking of cooking. More than one course? Cheese before or after? Dessert? What kind?
Then talk about what might pair well. Indian food? Maybe a Riesling. Fish? Leave the Cali Syrah home. Champagne to start with sharp cheese? Etc. etc. once you figure out some good combos, talk about the service. Mention that it’s nice to have different glasses for different wine. Now you can offer to bring some.
Voila. Fun!
What is “extra nice” to them, is probably a weekday wine to you.
I would bring over a $40 bottle of something that doesn’t require much contemplation and is quaffable. Something you would drink out of a rocks glass at a picnic table. Something that the stemware doesn’t matter. It feels like this is the type of set and setting you want before a concert (assuming you aren’t going to watch the orchestra). Leave the complex, aged, mysterious wine and high end stemware for one night when they come to your place and the wine is the focus of the night.
Maybe before I jump to this conclusion I should have asked what is the concert and what’s for dinner?
TW
This.
Just have fun and don’t sweat it.
Pretty much all of the suggestions here have merit. What’s best depends I think on the particular friends and your relationship with them. Specifically, I have friends where I would and have take stemware (along with decanting equipment) and others where I moderate the wine selection.
If you are going to take stems (and it’s the first time) absolutely discuss ahead of time. Avoid saying or implying their stems suck. For that reason I’d be careful about gifting stems (strong implication there).
In general, the suck it up and chill out suggestions are the best.
But if they really are “good friends” and know you have wine geek tendencies bringing a new set of decent stemware is not out of line at all. Don’t go for a cheap, ‘on sale’ from a discount store set. Get something that looks real nice to them. You don’t have to go very far up in price to find that for most people. You guys can probably have a chuckle about being wine snobs if you are good friends and they can have a nice new set of stems to impress their other guests with.
I think it’s more about what your actual relationship is with this couple. The definite default position is to bring something THEY will like and relax no matter what you drink from.
The stems I use every day are Zaltos at $60 per stem. That would be one expensive gift to someone who asks me to bring some extra good wine. And while I am at it, I don’t think hosts should ask their guests to bring anything. Poor manners, in my snotty, condescending book. 
Thanks to all for input.
Clearly there is no right answer, given the varied responses.
I’ve made my decision. Will report back tomorrow.
At which point you will be told made an idiotic, inconsiderate decision.
You’re staying home citing Coronavirus concerns?
I’ve done that many times. It’s a nice gift, and then you don’t have to drink from condo wine glasses when you’re visiting.
In this instance, if it’s not the time for wine glasses as a gift, I think you could just call and ask about bringing glasses over. “I know you are planning a gourmet evening and I’m picking some special bottles to bring. They’ll show best out of these glasses I have — do you mind if I bring them over?
Then listen for the reaction. If she sounds kind of weirded about it, or says “why bring wine glasses, I have perfectly fine ones,” then just agree and let it be. Maybe adjust your wine choices accordingly.
Do it in person or on the phone though. You won’t get the nuance you need over texts or emails.
That’s the ticket. Take your glasses and conduct a taste test between your great glasses and the bad glasses your idiot hosts provided. Try to convince everyone what a genius you are and how your hosts are a bunch of dolts. What a great idea!
Will you ever be invited anywhere ever again??? Deservedly not.
Phil Jones
Yes, I end up here, too–one night, bring some fine wine, drink from their glasses, eat their nice food.
Bring a box of 8 nice glasses. (Not zalto nice but nice enough).
Taste and compare with them if they are good friends. They might learn something and won’t be offended.
Tell them hey these are yours! Enjoy.
Nice Friends/neighbours. No issue.
I just had someone ask me about stems - I sent them straight to Chris/Grassl.
I wouldn’t bring stems. Seems gosh to me, even if you bring wine. No way on god’s earth I would bring my own singular stem.
At a later date, I MIGHT give them some stems, not night of. We usually have our table set before people arrive. So they would be faced with replacing their stems with your better stems. That’s just awkward.
If you feel so inclined to have your stems, you should call ahead of time and ask and/or announce.
I think I’d just bring something very good. I think a decent banquet stem really isn’t going to ruin an excellent wine. Yes, and ideal stem is better, but an excellent wine is still going to be excellent.
Most of my wine liking “dinner party” type friends would have fun (knowing I can be a wine dork) doing a comparison with the understanding that there’s an overall agreement in the wine dork world that great stemware makes a difference, and “if I bring this bottle, it might sound lame but you gotta try it from these glasses I have”. My Coors Light BBQ neighbor… I wouldn’t entertain the idea. If the good cook neighbors are the type, then have fun with a wine tasting experience. It’s fun. On a similar point, I would put money on there being more craft beer geeks out there who would bring their own IPA, BBA stout, sour beer glasses to a dinner party.