All-Clad, no question. They are some of the best out there and will last you a lifetime. You can find this brand in lots of retail stores.
There are a few things to consider, however, with whatever material you choose. With All-Clad (stainless steel) it is important that you do the following:
-Do most of your cooking on medium heat. Most people get impatient and turn the heat all the way up to high which burns the food on to the pan and is a pain in the butt to clean. They also wonder why the outside is singed and the inside is raw...hello, no-brainer there!
-Let the pan heat up first before adding food.
-Once you put food in the pan, leave it alone until it is ready to be flipped. Don't poke, prod, lift the edge to look at it, etc. Unless you're stir frying at high heat (in which case you'd use a wok and the food should be moving a lot), the food will release when it is ready to be flipped. Flip/slide/poke/prod any earlier and it will stick to the pan.
-Take good care of your pans. Never put them in the dishwasher! Hand-wash them using warm soapy water and if there is stuck on food or stains, use something like Bar Keeper's Friend to remove it.