If you already had gold crowns on one or more of your front teeth, and the gold crowns are being replaced, then for front teeth you will most likely want some type of tooth colored crown so that it will look like a real tooth again.
The most "real looking" and natural will be an all-porcelain crown with no metal underneath. My favorite right now is the EMax porcelain material.
Another alternative type of tooth colored crown is porcelain fused to metal (often called a PFM crown). These have been used in dentistry for decades and are the standard treatment used by most dentists. However, because of the metal underneath the porcelain, these crowns don't look a natural as all ceramic (with no metal underneath) crowns. This is because light doesn't go through and disperse through the PFM crowns, whereas they do with all porcelain crowns. Generally the fee for all porcelain crowns are a bit higher than PFM crowns because it requires a little more time to place, and also the lab bill is usually higher as well.
You might want to refer to the cosmetic dentistry blog link below that has articles that show examples and discuss the differences between PFM crowns and all porcelain crowns.