Robo has hit the nail on the head. I find the Calphalon cookware works best for me. I also have some really good Magnalite (that is no longer made), that also works great on the glasstop. I'm not that fond of cast iron, but it works fine, too, as long as it has a flat bottom.
Wouldn't trade my glass-top stove for the world...it's so easy to keep clean. We wipe it off with a soapy dishcloth, wipe with a clean towel, and call it done until the cleaning lady come on Friday. She uses the special cleaner on it.
Another thing I love about it is the accuracy of the thermostats...both oven and top. It is an excellent appliance.
We get by with a little help from our friends