Choosing where it is best to do your investments depends of many factors. In the first place it is important how much you want to invest. If it is only a low amount you can best invest in your own country.
But in many cases a mix gives you the best result. It depends of so many factors and the risk you can afford. In this time I think it is best to invest in Europe, the economy is growing faster than in America at the moment. A few months ago it was the contrary. But Asien is also a good place to invest, but the risks are higher.
That is one aspect of the investments, then you have to make the choice in what kind of investments. You can invest in shares, bonds or better in mutual funds.
If you want to invest in bonds or mutual funds who invest in bonds it is best that you wait because if the rate of the interest is growing the value of the bonds slow down. I think if you can wait three or six months it is best to invest in european bonds, more safety.
I advice you to invest 70% in Europe, 20% in America, 10% in Asien.
In Europe a good choice is also to invest in emerging markets like Turkey, Russian and some others but not too much money because of the higher risk.
Investing in your own country is always good for the economy of your country but you have to see to your own profits. So I think if you invest the most of your money in a mix of European countries I think you get the best result.