Insightful Enchanter-

Very useful for those who plan to sneak in armor and still of a decent priority for any other player thanks to the ability to enchant rings and necklaces, this perk goes a long way to improving your noncombat capabilities, and can do some fun things for your combat ability as well.  Enchanting things with combat skills will also provide a considerable boost to your ability to survive and overcome conflicts, so you may want to invest for the sake of your Archery necklace or Two-Handed Weapon gauntlets as well.  While it’s possible to set your enchantments up with no skill increases at all, there are very few reasons to skip the option, and more than a few reasons to keep it (not least of which being that some NPCs will have skill ratings during the lategame that are impossible for you to beat without skill gear) and if nothing else you can use it to put together a set of gear for when you enchant that will make your enchantments even stronger.

Corpus Enchanter-

For all that skills are vital to extending the effect of your resources as you use them, there’s very little quite like having more of those resources to begin with.  This is of particular importance to characters who need to lean on all three of their stat pools.  Straight mages (who likely haven’t invested much in Health and even less in Stamina when there was Magicka to buy up), stealthy assassins and archers (who probably haven’t got too much Stamina and even less Magicka), and brutal warriors (who may have plenty of Health and Stamina but retain a 100-point Magicka pool) won’t see as much benefit here, but if you tend to mix things up and rely on combining spells with melee combat, then you’re going to need the increase to your pool-boosting enchantements all the more.

Extra Effect-

The Enchanting perk with the highest requirement, and it’s quite a doozy of a perk as well.  Putting two different enchantments on the same item is exactly the reason why your enchantments can mean so much compared to which armor and weapons you use.  Players who, up until they had this perk, weren’t sure if they should go for 20 Health or +15 Block can now have both, those who were using one Shock and one Flame weapon can now have a pair of Shocking Flame weapons, and any number of other combinations are possible.  There is one big point worth noting here, though- this perk only applies during the initial enchanting of the weapon.  Once a weapon has been enchanted, there is no way at all to replace or alter that enchantment- and that includes by adding a second enchantment.  If you want double-enchanted items you have to buy or find them clean, or make the original item yourself.  You also need to make absolutely sure that you want the two enchantments you’ve chosen together on the same item, because you’re not going to be able to change your mind at all and carrying around multiple of the same item can get prohibitive- both in terms of weight and, later on, in terms of whether or not you can find the materials to make multiple of the thing in the first place.