I can't really explain it better than just showing you
Alchemist build
Vanquisher build
Destroyer build
Diablo 2 builds
Amazon alone has so many builds associated with her. All of them offer something different.
If you notice in the alchemist build, the guy posting says there is no real difference between spells. He wasn't saying it in a bad way, but that about sums up why I don't like Torchlight. There is no difference.
BTW, I've been saying FABLE, when I meant FATE. Sorry about that. Both of them are about on the same "fun" level for me though

, but Torchlight is most definitely like FATE not Fable.