As an amateur pyromaniac, I'm always on the lookout for new fire steels. I recently got a Gobspark Armageddon Fire Steel and am impressed with it's performance. While it's a little bigger and heavier than others, it truly lives up to it's name by reigning down fire and brimstone mercilessly on helpless tinder. If I were going somewhere where I would be using a fire steel as my primary method for lighting stoves or fires, this is the one I would want to have with me (especially in rainy conditions). Here's a quick video comparing it to another popular fire steel:
What do you carry for a fire steel these days?