Which level of magic do you use the most (Heroes of Might and Magic III)?

Chain Lightning is certainly good, but I don't like Inferno, both in general and compared to other powerful spells. As a damage-dealing spell, it's not very strong, and I prefer to deal a lot of damage to a single target rather than a little damage to multiple targets. The exception, of course, is Chain Lightning – it not only deals significant damage to one target but also hits nearby enemies quite hard. But overall, I think a fourth-level prayer spell is better. It might not be a direct damage spell, but it provides huge advantages.