It depends on your preference! Sardines in water tend to be lighter and milder in flavor. They are usually canned with just salt or other seasonings, so they have a relatively neutral taste. If you're looking for something light and subtle, then sardines in water would be a good choice. On the other hand, sardines in oil tend to be richer and more flavorful. The oil can help bring out the natural taste of the fish and also provide extra flavor from herbs and spices that are often added to the canning liquid. If you're looking for something with more robust flavor, then sardines in oil might be a better option.