Considering taking frost as my element of choice for the first time in my playthrough, was wondering besides fire dragons and flame atronachs, is there anything else that shakes in their boots at an Ice Spike? I'm also wondering how effective the famous slow effect is too.

Hmmm....

Fire Wyrms. I would also expect anything that specializes in fire or is made of fire.

You can also make or buy Frost Aversion Poisons that could help.

Trust me, it's very effective even at higher levels.

In fact, the slow effect + the paralysis effect from the Deep Freeze perk make Frost magic extremely underrated.

The slow effect of Frost is very affective.. however most of the NPC's in the game are Nords...

As for enemies who are weak to Frost I have no idea.

I feel that people overestimate the representation of Nords among the bandits of Skyrim. Most of the bandits I encounter are non-Nords.

Most heavy warriors relying on stamina

Flame Atronachs and Ash creatures.

Beat me.

Any dunmer thats on solestheim? Not weak, more like they don't have any resistance.

I use to use frost whenever possible myself (except for obvious situations), however in general I've found flame to be more useful for myself, especially fireball for multiple enemies. Worth noting though is that my character isn't at the stage yet where she'll slow enemies, that would be a very useful skill.

All the three types have their uses, and I try to use them when most appropriate these days, defaulting back to fire if specialty isn't necessary. It seems it's personal though, but that works for me at the moment. Maybe when my mage starts slowing enemies that will once again change.

Deep Freeze is the best perk for melee mages. Cast a frost cloak and charge in. Saved my skin plenty of times.

Frost cloak + augmented frost 2 + deep freeze + using the ice storm or icy spear = watch out enemies. Sometimes they are barely moving, sometime frozen.

Frost cloak + augmented frost 2 + deep freeze + Dragonborn Frost using the Frost Breath Shout = encased and just hit them to shatter them.

Although nothing beats a flame cloak.

What makes the flamer cloak so good?

Next time you get caught by 3/4 bandits try a dual casted flame cloak and then switch to flame cloak in 1 hand and fireball / firebolt in the other, or even flames and watch their health go to the bottom. Sometime you do not even need to cast another spell.

Umm ... don't all cloaks do the same damage? I imagine you could do the same thing with lightning cloak and cast chain lightning. Is there some kind of glitch with the flame cloak that make it do more damage?

No glitch. Shock cloaks do shock damage, and act like sparks. Shock drains magicka from enemies. Frost cloaks do frost damage and slow down enemies. Acts like frostbite. Flame cloaks do fire damage, but fire actually damages enemies and instead of draining magicka, or slowing down an enemy, it lowers health and a dual casted one is not stronger, but reaches out twice as far.

Example, a single casted flame cloak, say it reaches out 3 / 4 feet. When en enemy gets 3 / 4 feet away from you he starts to take damage to his health. A dual casted flame cloak reaches out 2x as far, say 5 / 7 feet. So an enemy starts to take damage 5 feet away, and by the time they get close enough to hit you, they are almost dead, or dead. Depending on level. Plus any fire spell continues to burn for a few more seconds after it is cast. Hope that made sense.