I'd go for
Str - spells that seek to physically restrain the target (breaking/escaping a resilient sphere, evard's black tentacles, web, perhaps certain wall spells)
Dex - spells that can be avoided via quick reaction (AoE such as fireball and lightning bolt)
Con - spells that attack the body (Disintegrate, Cause Disease, Polymorph)
Wis - spells overcome by keeping a cool head or "grip on reality" - fear, insanity (this would make clerics good vs. fear, falling back on their faith in a deity)
Int - illusions
Cha - charms and domination
Cause Fear - Wis - You frighten them
Chain Lightning - Dex - They avoid magical lightning
Command - Wis - You control them
Disintegrate - Dex - They avoid your death ray
Hold - Wis - You paralyse them
Irresistable Dance - Wis - You make them dance, dance magic dance
Phantasmal Force - Wis - They see through your illusion
Polymorph - Wis - They resist transformation
Sanctuary - Wis - You make them think twice about attacking
Thunderwave - Dex - They avoid forceful thunder
Web - Dex - They avoid your webs
I'd go for
Str - spells that seek to physically restrain the target (breaking/escaping a resilient sphere, evard's black tentacles, web, perhaps certain wall spells)
Dex - spells that can be avoided via quick reaction (AoE such as fireball and lightning bolt)
Con - spells that attack the body (Disintegrate, Cause Disease, Polymorph)
Wis - spells overcome by keeping a cool head or "grip on reality" - fear, insanity (this would make clerics good vs. fear, falling back on their faith in a deity)
Int - illusions
Cha - charms and domination
Severe MAD should be a goal for the game, IMHO. The problem with MAD characters is that SAD characters are so much better. And that's wrong. Every ability should be important to every class in some way. If you want to have a low stat, you should have some consequences.Stormonu's list is nice, but in practice it might lead to severe MAD or characters who are completely average across the board.
I'd prefer 4e's method.
Intelligence can't be perception, because animals wouldn't be able to spot or listen.That said I can see another option, but it modifies some core ideas that have been in the game for two editions. Make intelligence perception, with illusions as the I notice a difference. Then make wisdom willpower, then make charisma similar to the difference above between strength and constitution. So strength is the actively resist physical things and con is the passively resist things save. Same here, wisdom is the passively resist mental effects and charisma is the actively resist things.
Intelligence can't be perception, because animals wouldn't be able to spot or listen.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.