"Steel Reign" on the PS1 had guided missiles that were controlled by the left analog stick and could be flown a pre-determined distanced before they would detonate (as soon as they ran out of fuel), be flown as scouts to get a lay of the land, and my favorite find your target in multi-player and veer straight up and detonate at just the right altitude to leave a large area of leveled buildings or trees along with your intended target. For a game over 10 years old it seemed amazing at the time, and the amount of practice it took to gain precise control of the missiles which traveled at near insane speeds made it even more of an awesome idea.
I think its the best arcade tank game I've ever played;and I've been looking for something to take its place ever since I broke down and sold all my PS1 games years ago to no avail.