If you just want my general opinion, I say go somewhere a little different, like Slovenia or Sicily.  But that just pertains to what I want to do.  You should include some specifics, like what you would like to see or do; nightlife, beaches, mountains, art, history, castles, etc.  A lot of people say they want to see and do a little of everything, which you can accomplish in 1 month, but that takes some indepth planning.  Spain, France, and Italy are all vast, you could spend 3 weeks in any of them and still not see everything.