I live a few meters from the city line of Burlington, and I teach at the University of Vermont.
I would probably prefer postcards that show the place you're sending them from: singular or unusual landmarks, landscapes, and so on.
If you have a postcard with a picture of a single animal on it, I have been saving these as a little collection for my son (who is two years old). We have plenty of ducklings, kittens, and domestic cats, so please choose other creatures. So far, he has a jellyfish, a whale shark, a penguin, an elephant, a sea turtle, a wolf, a dog, a goldfish, a zebra, a tiger, a lamb, a fox, a badger, a piglet, a cardinal, a chimpanzee, a horse, a marten, a boar, and an otter, among lots of other things. If you want to send him a message on the card, that's cool, too.
I also like "boring" picture postcards, of airports or motels or ugly buildings. Libraries or other university buildings would also be interesting to me, if you live in a town with a university.
Another thing I'd be interested in seeing is local food and drink, if you have any postcards that show pictures of the typical local foods or alcohol.
And if there are interesting rock formations or other geological oddities in your area, I'd be happy to get postcards of those, too. (I'm especially interested in formations called "Devil's [Something]," like the Devil's Punch Bowl or Der Teufelstisch, etc.)
PLEASE, if your postcard doesn't include a description of the image in English, tell me a little bit about what I'm looking at. It makes a HUGE difference in my enjoyment of the card!
I would really rather not receive multi-view postcards. I prefer single views. But really, I'm just happy to get any postcard that could only be found in your town or your part of your country.
My expired cards are, sadly, too numerous to keep track of. If I see a card has expired, I often try sending a duplicate one if the recipient is still active in Postcrossing.