Fireball is the worst spell, ever. It's a nightmare on every level that counts, and the worst part about it is how popularly accepted it is.
For starters, it is kind of a bogus joke. it's made from bat guano, so you are basically just using gunpowder on the spot. Doesn't feel very magical when you think about it. Yet it is considered an iconic spell.
Casting the spell should be a war crime. Not only does it burn things to death (a horrible way to go), it is often deployed indiscriminately on friend or foe alike. And it causes massive collateral damage to the surrounding infrastructure and nature. The idea anyone can use such a spell and call themselves good is appalling.
Mechanically speaking, the spell is boring. It just deals damage to anything in the area and sets stuff on fire. There are no really cool ricochet shots, no demonic badgers, no bending the natural laws of the world around your little finger, nothing but damage and burning. You could accomplish damage and burning by using a torch.
On the DM side of the screen, it means that you can't use rooms full of small fry without them getting mowed down in an action. Think of the kobolds, they are monsters too. They have hopes and dreams and they smell bad when they are all burning in a room together, seriously.
No, other powers were significantly better. It was a Wizard power, and Wizards were controllers. The damage was the only effect of the power, too, while all other powers for controllers generally have riders. It was a level 5 daily that dealt 3d6 + mod to friendly and hostile alike. That makes it on par with level 7 Wizard encounter powers, and only one die more than level 3 Wizard encounter powers. It was laughably bad.
Still not as bad as what they did to Knock.
