Well, the US is the only country I've ever lived in, and from what I've seen, it's a fairly good place to live. However, some fields, such as IT and medical research, are better served in another nation. The former is being torn apart by IP lawyers, the zaibatsu-esque corporations they represent, and a legislature that doesn't understand it, except for what the aforementioned corporations tell them. The latter is restrained by the religious right, which holds so much clout that they can even prevent public schools from teaching students about evolution.
If you're not working in or looking to work in one of those fields, the US is a great place to be. But if you want to do anything fruitful in IT or medical research, it's not a good place to be. That's why I'm planning to leave.