I've been in Wacken twice, 2011 and 2012, and I love it! Even the last year with all the mud, I had a very good time. The problem was that It was raining for one month without stopping, so when we arrived there and it started to rain again, the mud was everywhere, and it was deep and so slippery! But funny, because there are always people who like to swim naked and drunk on the mud, that is a great show hehehe.
Wacken is the perfect holiday of a metalhead because of the heavy metal atmosphere, that involves everywhere and everybody in the town. The food is great and cheap, and there are a lot of different kinds. But to taste viking food, or to see an entire pig rolling on the skewer while roasting, is necessary to go to Wackinger Village. The stalls have amazing things, as well as the ones in the Metal Market. And the sound of the concerts is great. I will go next year, because is the 25 anniversary. And for those people who think than Wacken is not affordable at all, I think it depends of many things, but I didn't spend so much money when I went and thinking about all the things that Wacken offers, is worth going once in your lifetime!