Need advice

Where do you plan to enter Spain? How do you plan to travel: car, public transportation? It is possible to combine Barcelona with Ibiza and then on to Valencia, by taking first a ferry from Barcelona to Ibiza and then from there on to Valencia to continue to Sevilla. Ferries do take some extra time though, although Ibiza-Valencia will only take a couple of hours

rohinig,

I have no idea of your experience, so I must state the obvious. Transportation time and how big a hole it punches in your two weeks, is key.

Generalising, at least two full days for each city's 'sites', but do you want to use those cities as bases for side trips as well?

Drop at least Ibiza, perhaps.

Best wishes.

Andalucia is a region, not a city, so keep that in mind. There are a lot of cities in Andalucia.

Posts like yours often get the obligatory "If you don't spend AT LEAST 7 days in Seville you are an idiot" type response. Seville is fine, but we spent one day there and it was enough for us. If you get any responses telling you that you MUST spend at least 7 or more days in one place, just ignore them. For my taste Cordoba was a much nicer and more interesting city and that's in Andalucia. One or at most 2 days in Valencia would be plenty.

One of my friends once described Madrid as having a New York City kind of feel to it and Barcelona as having a Los Angeles kind of feel to it. I think that's fairly accurate. Each has its fans. I'm American and I'll be honest with you I despise Los Angeles, but I loved Barcelona. Madrid is a good place to visit, but on a short trip you can't go everywhere. You can always go back to Madrid some other time.

I would Barcelona compare to San Francisco and not to Los Angeles In both Barcelona and San Francisco there are city centers that can without any problem explored on foot and by public transportation and they are fine night and day. There is an open atmosphere in both cities. I like both cities very much, but do not really care for Los Angeles.

Definately go to Madrid!
Much of the stuff in Art History books is at the Prado and Thyssen-Borzenstien Art Museums.
And the Royal Palace compound is not to be missed.

The "El Bosco Room" on the Prado is all Herronymus Bosch.

Ignore people who tell you that posts like yours often get the obligatory "If you don't spend AT LEAST 7 days in Seville you are an idiot" type response. The only poster on this forum who believes in that (to the point of obsession) is jman98, who spends most of his time on Thorn Tree repeating the same old crap that he already posted 100s of times before; also bear in mind that despite various requests from other regulars, he has never been able to provide a concrete example of the type of behaviour that he accuses others of (why? because he can't find one)

Sorry OP, I had to get this off my chest. As for your itinerary: given the distance between the places on your list, I think you probably enjoy your trip more if you concentrate on one or two regions, for example Barcelona/Catalunya and Sevilla/Andalucia (which ones you choose depends on what places attract you most, of course).
Madrid is the kind of city that grows on you the longer you stay there, and has a couple of world-class art museums and great nightlife, so it is worth considering if you're willing to give up some time in the other areas.

All guidebook safety chapters say money belt. Spain and Portugal have sticky fingers.

P.S.

One of my friends once described Madrid as having a New York City kind of feel to it and Barcelona as having a Los Angeles kind of feel to it
I suspect that friend has never visited any of those cities then. Barcelona having a LA kind of feel to it? Thank god that's not true.

Actually, I think comparing Barcelona/Madrid to Los Angeles/New York is a silly generalization; of little or no value.