I have been a big fan of Calphalon for many years. What turned me on to it was the wide availability, and some personal reviews from friends and family. My first 12 inch non-stick pan lasted me 4 years of constant beating before it finally died on me. I replaced that particular pan with a 6 QT Unison Saute pan and I can't say enough about it. It can take the high heat of the stove, hot oil on the surface, and going into the oven up to 500 degrees F/ 260 Celsius. The clean up is fantastic, and supposedly you can put it in the dishwasher, but I fail to see the point when you can wipe it out easily enough. It's still harder to get a good crust on meats with a nonstick, though I have to admit this new series of cookware (Unison) has gone the distance to try to address this problem with a slightly textured surface of the pan.
As for All Clad, I like their line of Stainless steel. I've never had an issue with the pan not working well or heating evenly, and I have the dreaded electric stove! I have never tried their copper core set as the price tag was a little to hefty for my budget, but the 10 inch pan I have gets a fantastic sear on meats, and cleans up easily retaining it's beautiful shine.
I recently bought a Le Creuset Dutch Oven, which is a an enameled cast iron pot. Occasionally this thing is hard to clean, but I think that was partially my fault for being lazy and leaving it to the next day. :) I can do just about anything with this thing, and I often do. I love cooking ribs in it, large casseroles, soups, it can easily be your go to one pot meal cookware. Well worth the price, which I have to admit I was skeptical about. I didn't take the plunge until a friend of mine bought one for herself and just raved about it non stop to me.