Just got back from Spain and thought I would share our itinerary as we were pleased with how it went. Took trains between every city (very easy to book and use)
Madrid (5 nights): we are not art/museum people so we didn't go to any of the galleries or museums. We are foodies and love good wine and history. We loved walking around Madrid and exploring all the plazas, sitting at a cafe/bar and watching the world go by. Booked a day tour through Viator to Toledo and Segovia. It was great but a bit rushed, I could have easily spent all day in Toledo. Everything in Madrid was surprisingly walkable. We used the metro once, but the weather was enjoyable and we preferred to get around walking.
Cordoba (2 nights): Loved it here, the Mezquita was amazing (if you go first thing in the morning it is free). The food scene was great, loved getting lost in the narrow alleyways. 2 nights was good for us though as it is quite small.
Sevilla (4 nights): One of our favourite places. So much to see and do. Spent a day walking in Tirana. Couldn't get tickets to the Alcazar but able to get tickets through Get Your Guide for the Cathedral. We were very impressed with the cathedral. Did a walking tour which was great. I don't understand why Rick Steves seems to discourage free tours. I know they aren't "free" but they are still a great bargain. Plus I don't have the funds to spend the money he advertises for the private guides. Went to a flamenco show at Casa de la Memoria which totally exceeded our expectations! Also went on a food/drink and history tour with Devour Tours (our favourite company for food tours) and it was fantastic.
Granada (3 nights): tied with Sevilla as our favourite. Loved the Alhambra, took a "free" walking tour (fantastic and use Guru guides to find the tour), explored the Albaicin neighbourhood and enjoyed all the tapas! Go to La Clausura for dinner. Very local and amazing food!!
Barcelona (5 nights): our lest favourite city. It was so busy, waiters were always asking for tips ( and we avoid all restaurants by tourist attractions as a rule), dirty and just honestly didn't do it for us. We did a Devour food/drink and history tour which was a highlight. Sagrada Família was impressive but I like old gothic churches better. Park Guell was overcrowded and very underwhelming. Walked a block on the Rambla and left as there was nothing we liked (didn't help with all the construction). We stayed in the El Born area and loved it there. Really enjoyed walking through the Gothic quarter. Took a day trip to Baga (loved it here) and then Andorra (underwhelming, the scenery on the way there was a highlight).
Wouldn't go back to Barcelona but would revisit the others in a heartbeat!