Bulldog,
You've received some good advice so far regarding your entry door. Now, what are you doing to secure other points of entry to your home?
You can put the strongest steel door in an opening that has been framed out with iron I-beams, and a thief will bypass that security and enter through a basement window. It's important to consider EVERY point of entry into your home.
Double cylinder deadbolts are great for preventing a thief from taking your stuff out the front door after he has gained access through a window, but if you have to leave your house in a big hurry (fire, etc.) they lose their appeal quickly. I'm not against double cylinder locks at all, but you have to weigh the risks versus benefits.
What have you done to secure the windows in your house? Most thieves aren't going to enter through the front door, so you need to consider this fact. Do you have an attached garage with access to the house? How strong do you think your garage door lock really is? If you have a garage door opener, forget about it, they most certainly can get into your garage. Concentrate on securing the door from the garage to the house. And don't put anything you're not willing to lose in the garage.
Since your house is older, you probably don't have egress windows in your basement (if you have a basement). Consider putting lockable iron grates over window wells if your local fire code will allow it. Again, it limits your chance of escape from the basement in an emergency, but honestly, most people couldn't jump up five feet and pull themselves out of a 2 to 3 square foot opening anyway. Thieves love basement windows.
Consider more than your front door and the lock installed on it in your burglar-proofing plan.