Suggestions for accommodations in Madrid, Granada and Barcelona

Not to give an unhelpful response, but if you provide a bit more info on your budget,
interests, and preferences (e.g. location, service level, dining), you will probably get
better replies.

I will ask if you are open to renting an apartment instead of a hotel room. 3 of you can
probably get a nice 1BR apartment with a sleeper sofa for less than a hotel, if you are
open to going to a grocery store and the tradeoffs for apartments vs hotels. I like to
rent an apartment for at least parts of a trip for the larger amount of space, ability to
have meals in the apartment, and (if you specify it) have a washer in the unit to do
laundry midway through the trip.

Thank you! I just edited the question. Thank you for those suggestions.

AirBnB is what we do.

Steve's guidebooks for those area have excellent recommendations for those area. If you don't want to buy the guidebooks, then check them out of your local library.

Granada is full of apartments for short term rent. You can go on Booking. com and click on apartments and icons pop up all over the map. It's nice that Granada (and Spain) is a relatively inexpensive place to travel to.

Laurel Suites Apartments looks like a really nice property with great customer ratings and a great price.

We stayed just below Alhambra when we were in Granada at an apartment for a weekend. It was so nice getting out into the community and going to the local market, etc.

Thank you for the suggestions! I just downloaded the Rick Steves book on our Kindles. I have booked through Booking.com in the past so thank you for the advice.

I stayed at Ferala Suites Granada last fall, lovely apartment for 64 Euros a night,
very centrally located.

With an apartment rental, you're more likely to need to figure out where things are
nearby on your own. I.e, no hotel concierge, staff, etc., as well as figure out local
transportation options since you may be a bit away from major streets, subways, etc.

I think all 3 cities have multiple accommodation options, but I would lean towards
a hotel in Madrid and apartments in Granada and Barcelona. Granada is fairly
compact and the subway in Barcelona covers most of the city.

I have used booking.com a great deal in the past. This year it seems to me the rates there are most often quite a bit higher than for a direct booking, so I'd recommend you try to find the website of any hotel you're considering to see whether you can substantially beat the booking.com rate. Of course, hotels often have rooms of different size/quality, so some effort may be required to be sure you're doing an apples-to-apples comparison.

We walked everywhere in Madrid and stayed at Hotel Catalonia Plaza Mayor.

In Madrid we stay at Hotel Europa at the Puerta Del Sol. My wife likes the location and sitting outdoors at the adjoining cafe for people watching.

In central Granada there are the following laundromats:
Lavanderia Autoservicio Speed Queen Granada Centro at Cta. del Progreso, 2, Centro,
Laundromat Lacolada at C. Elvira, 85, Centro, and,
Wash & Dream at C. Fábrica Vieja, 14, Centro

Usually the how to use directions are in both Spanish and English.

For Barcelona, we loved Hotel Praktik Rambla.