What type of frying pan does not warp? I have a glass smooth-top stove. Every large frying pan that I have bought so far has almost immediately warped so that the bottom is no longer flat. They all end up concave -- like a wok but less pronounced -- so that they perch with a small spot in the center of the pan touching the burner surface.

My lazy side prefers non-stick, dishwashable pans, but all ideas are appreciated.
You have to make sure to buy a heavy duty, preferrably professional grade pan.  Thick base.  Most important.   I have owned my pans for about five years, and nary a warp.  Completely flat.  I also have a glass top stove.   Note to the wise, do not use a dishwasher to clean good cookware.  Always clean pans, pots, knives, etc. by hand.

Any good restaurant supply house will have good quality non stick pans.  Also, I' m not sure where you live, but many large department stores (JC Penny in the States, the Bay here in Canada) have good quality wares.  Be aware, they do not come cheap, but they will not have to soon be replaced.