Grocery Aisle Smackdown: What's Worth It, What's Not

Mayonnaise: Olive Oil vs. Regular

Our choice: Olive oil

Why: Even though mayo made with olive oil (such as Hellmann's Mayonnaise Dressing with Olive Oil) still contains some soybean oil, which is the primary oil in most regular mayos, it has about 40 percent less fat and calories than the standard spread. It's a nice compromise between full-fat and light mayo, which has about half the fat and calories of the olive oil version—but tastes like it.

The only drawback: Some may notice a difference in taste (the olive oil adds a slight tang).