I absolutely love Valencia!
I had some friends living there and I used to visit quite often. I was there during Fallas 3 years ago and it was amazing! I didn't think I could like so much something as the Mascletà (it's like fireworks, but during the day, that is: pure noise!). The Cremà was just one of the most incredible things I've ever seen (it's the burning of the huge sculptures, fallas, that are built for this feast). I was on the roof of a friend's house, just 200 metres from the huge thing being burnt down (it was about 4 floors high!).
LOVE IT!