Add a new graphic card to my intel gma x4500hd

First of all, you need a low profile card. That means that the highest you could go, with the best performance, would be a 5670 or 5570. But please clarify what you intend to use the card for. If you don't game, you don't need the card with the "best performance." A 5570 would be major overkill if all you do is watch movies and browse the web. If you don't game, there might not even be a reason to upgrade at all.
P.S. If you decide to get a new card, you better upgrade the power supply as well. 220w just won't cut it for even a moderately powerful card.