Wasn't at Valencia and was only a few days old for Preston, but my fav away days oddly enough are both 0-0s.
The first one was Birmingham on a freezing cold new year's game in 2008. They were top of the table, but got booed off half time and full time because they couldn't get the ball off us. We should have won but Scotland had an off day and their keeper was excellent. But we were brilliant. Allen and Britton ran the game.
The other one was Anfield under Brendan in our first PL season. Again we should have won, but Reina was brilliant and we left our shooting boots at home. We got applauded off the pitch by the home supporters. Never been more proud of Swans than that day. Many say that got Brendan the Liverpool job.