So, what are people using for lunch containers these days?

I love bringing my lunch whenever I can, but I stick to non-soupy stuff since I've never quite found a trustworthy container yet. A few weeks back I thought I'd try my luck again with a Lock & Lock holding some soup, but it found its way out and all over the inside of one of my panniers. Luckily I had my work clothes in the other pannier, but the mess was there regardless.