Legos are great for all ages. They now have an "architect" series that you can find at Barnes and Noble. My 9yo has been a serious lego builder since age 4 and doesn't show any signs of disinterest with age! I recently discovered "enginos" which are similar to legos for the "builders" out there. Here is a link to their site- I purchased a set for Christmas at Amazon.com so I can't give a full review on whether they're a hit or not-but I'm thinking they will be!
http://engino.com/mega.html