They dropped this on the recent State of the Game stream. They are asking for the community's assistance in prioritizing their bug fixing process. I think this is a pretty decent gesture from their part. I urge you, please go to the official forums (thread linked below) and post your bug list. Let's help Massive make this game great again. http://forums.ubi.com/showthread.php/1486437-WANTED-–Most-annoying-bugs
Thanks for posting kiwi, will head there now and slap my top 10 down. Also if anyone can't think of 10 off the top of their head you'll find a plethora of good suggestions already posted on the post linked by kiwi.
Now they are doing a survey on skill usage in the game. Remember, this is about as close as we are going to get to a direct line to the game devs, so please go and have your say.