>Fire
>Electric
>Ice
The main three. You can add
>Earth
>Wind
>Ice
But some people will put Earth with water or fire, Wind with electric and Ice with water. I think you can have any element separate with its own properties with some synergy in other elements.
>Dark
>Light
>None/Void/etc.
Here's where the cutoff is. Usually Dark/Light balance each other out and None is just a stronger generic element, usually endgame stuff. I like Pokemon's way of handling elements, but to each his own.