I did a search of your other posts. It would really be helpful if you would include more information in each new post. You wrote in one of them that you are flying R/T Barcelona arriving April 22. It helps to know the time of year.
Madrid Allow a full day for the Prado, it's huge. The audio guide is very good. Plan in advance what bits you most want to see and figure out where they are. Their website has lots of information. The Thyssen is much smaller. Roughly speaking the Prado has paintings through the 18th c. The Thyssen carries on from there with lots of Impressionists. The Reina Sofia follows the saga from the 20th c. The Thyssen and Reina Sofia are smaller, allow 2-3 hours each. The Royal Palace included several small interesting museums, plan on several hours. I really enjoyed the Naval Museum (take passports), much about the Golden Age of Exploration. It's on the boulevard between the Prado and the Thyssen. The San Miguel Market is a great place for tapas - lunch or early supper. I liked the HOHO buses, but the commentary was dull and poorly timed. Then someone suggested listening to the kids' channel - much more interesting. Since you are planning day trips, stay somewhere near the metro for easy access. My choice is the Europa Hotel on Puerto del Sol, easy to get to/from the airport and train station by cercanias/metro just meters away, central location, great staff.
Sevilla First, Granada is NOT a day trip from anywhere. If you want to visit the Alhambra, you need to spend 2 nights in Granada. You can get there by train/bus from Cordoba (2 hours) or Sevilla (3+ hours). Then fly to Barcelona. Ronda is about a 3 hour ride from Sevilla. You could day trip to Arcos (one of the pueblos blancos) from Sevilla - take the train to Jerez, then the bus to Arcos. I think there are buses directly from Sevilla, but they are few and far between. If you want day trips, go to Jerez for the horse show at the Royal Equestrian School and a sherry bodega tour. Cadiz is also a good day trip from Sevilla by train. You could even combine the two, though it would be a very busy day.
Barcelona I agree with Sandy's description of the Picasso Museum. If you are fans of Picasso, you will find it interesting to see his development. The museum focuses on his very early years (teens) and there's a lot about the development of cubism. Not much else. My favorite modernisme sight is the Palau de la Musica. The TI's modernisme walking tour was excellent - a great introduction to the city's architecture and an eye-opener: there's a lot of moderisme that you can easily walk past without seeing if you don't know to look for it. Don't go out of your way to see Las Ramblas - you will walk through it more than once or twice and that suffices. Go to Figueres early, spend the morning at the museums, then stop in Girona on the way back for the afternoon/evening. You have nothing on Montjuic???? MNAC? Miro? Magic Fountain?