Seville or Valencia. Which city do you recommend?

I advocate them both. You can't miss.

Seville has more old charm. The cathedral is immense and stunning, as is the the moorish Alcazar. There are numerous other buildings Moorish, Mudejar, and Gothic that are worth seeing. The tapas are very good, the ideal flamenco may be here. The art museum has some very good Spanish Baroque paintings (though it won't compare with, say, Madrid, the museum is superior than Valencia's). There is a lot of tradition here, with a blending of cultures, and more laid back.

Valencia is more modern (though the old city has its charm, and the cathedral is nice but not as impressive as Seville's). The Art Noveau market is a treat, and there are a lot of parks where the river was drained (make sure you climb on Guliver). The architectural highlights are at the modern Ciutat de Arts i Ciencias, a complex designed by Calatrava. Good science museum and the best aquarium in Spain. Paella was born here. Valencia is near the beach, which is a couple hours by train from Sevilla. Nightlife is a tiny more relaxed here, but fine in both places.

Overall, I liked Seville a tiny better because of the history and charm. But obviously, I liked them both. Either way you made a good choice.

it's got almost everything that seville has got, plus a beach!!

to be fair to seville, it's beautiful, and if you want sightseeing, it wins, hands down.

but we found valencia smaller (and therefore easier to get to grips with geographically), friendlier (because it's smaller. massive cities are always less friendly), and it has a beach!!

AND it's got new things to see, like architecture from the 20th century by calatrava.

AND you can park. sometimes.

but seville is great too. if you choose seville, treat yourself to one night in the alfonso XIII. you'll remember it forever!

Okay, so I lived there, and it's kind of like a second home to me, but it's definitely more MY style…more romantic, more dramatic, very colorful! Then again, paella was invented in Valencia. I also am DYING to see the new science city, so…more of the modern? Go to Valencia (not to insinuate that there isn't a great old quarter). More into the romantic/moorish/flamenco/old Spain - go to Sevilla.