Ultimately, the buying decision is going to depend on your needs because there is no clear must buy in the midrange at the moment. Previous-generation DirectX 9 cards outperform their replacements, but the new generation of cards have DX10 support and better HD video capabilities.
I guess if you're after a mainstream graphics card with a good set of home theatre features and respectable performance in both DirectX 9 and DirectX 10 games, Zotac's card looks to be a better purchase than the Radeon HD 2600 XT, but it's a bit expensive for our tastes at the moment. You could say Zotac's GeForce 8600 GT ZONE Edition is a jack of all trades, master of none at its current price.
