We recently tried to use cast iron for most of our cooking, but I ended up buying one nonstick pan because we need something that's quick and easy sometimes.
My last nonstick pan lasted just over a year (according to Amazon), and I recently read that they were designed only to last a year - year and a half! I throw them out at the first sign of scratches now that I have kids. I probably wouldn't really notice until it was more scratched pre-kids.
How long do your nonstick pans last?