We've been without a microwave oven for about 9 months now.
This is not because we have some sort of philosophical objection to microwaves; the reason is much more practical. Before we remodeled the condo, there was a built-in microwave above the stove, which doubled as the no-vent/recirculating range hood. We knew that we didn't want this 1980s-era microwave, and we replaced it with a dedicated range hood:
Our initial idea was that we would get a countertop microwave. But once we'd moved in and sorted out the kitchen, there wasn't really an obvious place to put a microwave, because there's just limited counter space, alas.
So we've been doing without. This means we've had to explore substitutes for how we used to use the microwave. Like, how do you reheat leftovers without a microwave?
We use our oven or toaster oven. The room we might have given over to a microwave is taken up by a small toaster oven. That appliance is more useful than a microwave, I think, because it can heat and toast and broil. I make toast all the time, and we have no toaster-toaster, so this is a daily-use device for me.
One of the advantages of a microwave is that it's fast. But heating things in our little toaster oven doesn't take that much longer. It's a little oven, so it heats up pretty fast. It also has a convection setting (which I think just means it has a fan that blows the hot air around). All in all, what might have taken, say, 2 minutes in the microwave takes maybe 8 or 10 minutes in the little oven.
We heat things on the stovetop. Anything that's got liquid—soup, stew, whatever—we can throw in a pot and heat on the stovetop.
There are definitely dishes that would be easier to reheat in a microwave. Leftover pasta, for example. What I've been doing is putting these into a pan on the stovetop with a glug of water and a lid. It's not perfect, since it inevitably steams whatever you're reheating, but it's tolerable.
We (mostly I) heat things in a frying pan. Some dishes can be fried or refried. Heat a splash of oil in a frying pan and toss in your leftovers. If I fried up hash yesterday and have leftovers (unlikely), I can reheat it by giving it a short version of the same treatment again. And if we've got something like leftover rice, I can steam it again, or I can make fried rice.
I never much liked defrosting things in the microwave anyway. These days, if I have to defrost a hunk of hamburger, for example, I'll put it in the Dutch oven on very low heat on the stovetop.
And then there's popcorn. I love me my popcorn, but I never used prepackaged microwave popcorn anyway. I did have a series of microwave poppers, but they have an unfortunate tendency to break. So I went to the discount store and got a cheap 6-quart pan that is my dedicated popcorn popper. I heat it on the stove and do that classic thing where you shake the pan as the popcorn pops merrily.
I don't miss the microwave as much as I thought I would. It's been interesting to, in effect, return to our pre-microwave days. I didn't grow up with a microwave (back when they were known as "radar ranges," ha), and it wasn't ingrained in me to rely on it. We might still get one someday, but I think that the longer we make do without it, the less likely it is that we'll want to house one more bulky appliance in our limited kitchen space.