Another thumbs-up for Barcelona from me. Did it last year and it was absolutely fantastic, I'd only done the one marathon prior to (Edinburgh in 2011) and it made that look like a village fete fun-run. The atmosphere, the build up, and the course itself were unforgettable experiences.
Think it started at 8.30am, and it was still dark on the walk down to the start line, then whoosh, at about 8am, the sun came up, the music was booming and it was like a kaleidoscope of colour!
Cheesy and predictable I know, but they played Freddie Mercury's 'Barcelona' beforehand after hyping it up on the mic; "This is OUR City, this is OUR song". It was proper hairs-on-the-back-of-your-neck-sticking-up stuff, everyone in the pens was buzzing!