Best site I have found is:
http://www.eyeball-surfcheck.co.uk/
I have found Matt to be the most consitantly accurate and honest forecaster around. They do tri-weekly email updates as well as updates live web-cam updates. They also have a lively community and forum on there too.
Be careful as SOME forecast sites are based from a surfboard business that run nearby the beach they report on. Now it's of course, the better the surf - the more punters they will have hiring surfboards, buying t-shirts etc.
It could therefore be in their very best interest to "big-up" the report a little. Maybe call a 1foot barely surfable wave a 2foot and perfect wave. Maybe hang around long enough to get a photo of the one off rogue decent wave on a generally flat day.
Best advice is to check a few sites out.
Even better is to learn to forecast waves yourself - all the data you could possible need is out there - it;s just a matter of understanding it. Try these too:
http://www.oceanweather.com/data/NorthSea/index.html
http://www.metoffice.gov.uk/weather/cha ... ation.html
http://www.poletopole.org/flash/viewer.php?MID=1