What will you cook most? Stainless-steel skillets (with an aluminum or copper core) are ideal for browning and braising. However, nonstick pans are better for low-fat cooking, since they allow you to cook foods such as eggs without oil. A cast-iron pan can offer the best of both worlds, with a natural nonstick surface that still allows for searing. Cast-iron skillets can also go from stovetop to oven (to brown a frittata, for instance), but most other skillets are also oven-safe up to a given temperature.
How strong are you? Though they have many advantages, cast-iron pans are very heavy -- a possible problem for users who don't want a workout in the kitchen. Perhaps more important than a skillet's weight, however, is how it's distributed. A pan with good balance and a well-constructed handle will be a lot easier to maneuver than one with a heavy base and an undersized handle.
What kind of cooktop do you have? For a smoothtop electric range, you need a skillet with a flat bottom to make contact with the surface. In addition, if you have an induction cooktop, you'll need a skillet made of a magnetic material, such as stainless steel or cast iron. (If you're not sure about a pan's construction, you can test it by sticking a magnet to the bottom.)
How much time are you willing to spend on cleanup? Another downside of cast iron is that it requires extra care. It should be cleaned with little or no soap, dried by hand and oiled regularly to maintain its finish. Nonstick skillets also require hand washing to protect their coatings; however, their slick surface usually cleans up easily. Stainless steel is the toughest kind of cookware to wash by hand, as food more readily sticks to it. Many stainless-steel skillets are billed as dishwasher-safe, but experts say hand washing will keep your pans in better shape.
One of the newest trends in cookware is the rise of so-called green nonstick skillets. These pans use a ceramic or silicone nonstick surface that does not contain polytetrafluoroethylene (PTFE), the major chemical component of Teflon. Some consumers are concerned about PTFE because, when heated to very high temperatures (at least 500 degrees Fahrenheit), it can produce fumes that are deadly to birds and can cause flu-like symptoms in humans. However, PTFE-free pans generally don't do as well as Teflon in professional tests.
There are some signs that green skillets are improving; in Good Housekeeping's test of nonstick cookware, for instance, a PTFE-free pan was one of the top performers. However, there still aren't enough user reviews for the newer green pans to confirm how they hold up over the long term. Until green pans improve, a well-seasoned cast-iron pan may be the best choice for users concerned about PTFE.