A.K.A. the bread knife, a serrated knife is one of the few really essential tools to have in your kitchen. It not only slices bread, but it's scalloped edges will cut through other foods that are tougher on the outside than the inside (like tomatoes and peaches) without bruising.
The best part is, you don't need to spend a fortune. Don't bother with Henckels ($67.95?!) and Global ($79.00?!!?). And don't even consider something like the Shun Elite at a whopping $189.95? Forgeddabowdit. You will never find knives like these in a chef's kitchen.
This is one time when you can be frugal. A bread knife rarely, if ever, needs to be sharpened. As long as it's not flimsy and has a good handle (and no one uses it to cut through wire or branches as often happens in our kitchen), it will last decades. The pros don't waste their money; neither should you.
Here are a few good, inexpensive bread knives: