Heroes of Might and Magic is an excellent turn-based game that gave you control over magic-wielding heroes and the mystical creatures that would follow them. Each major hero type had its own special skill, like the necromancers bringing their dead back to life as skeleton soldiers.
The game could be infinitely re-playable. There were plenty of castle types to choose from and even more maps. The spells available added on another layer of variability.
Honestly, I still think about breaking this one out every once in a while. If only my computer knew how to run DOS. Fortunately, the newer versions still stay true to the original, almost to the point where it seems like you are playing the same game, just with newer graphics and some rules tweaks.