Necklace, rings and bracers/gauntlets/gloves are the most flexible, with enchants for every build.

Main armor/clothing piece has less enchants, but still allows for a lot.

Boots are not very good for most mage builds, having mostly thief/warrior enchants.

Helmets on the other hand are great for mages, good for thieves and awful for warriors.

So yeah, just something I wanted to share after anolysing enchants.

Boots can be enchanted with shock resistance, which is very useful for mages.

http://www.uesp.net/wiki/Skyrim:Resist_Shock

Here too: http://www.uesp.net/wiki/Skyrim:Enchanting_Effects