Reply to European music festivals around Halloween?

Me and my girlfriend were planning a trip away to some city in europe around halloween time, probably before, and we are both indecisive as hell, so we decided to just find a good music festival(we both have very wide ranges in tastes) and go to the city its being held in for a few days!
only problem is, we dont really know where to start, so i turn to you, DJTT, for help once more!
any suggestion is welcome, in and around the end of october time, 1 day festivals are completely acceptable as we wont be camping, and we were believeing about I <3 Techno but it might be too late for us!
thanks