Frankly, they're almost all quite useless by themselves. Unrelenting force might help get a few hits in while they're down and good for crowd control. Dragonrend is great but doesn't do damage. Storm call is also awesome, but damages my allies who are NOT pleased. And is it just me, or do fire breath/frost breath deal almost no damage? I'm assuming it might have to do with the fact that they don't level with you =/

Unrelenting Force, at level 3, can kill pretty much everything it affects if you throw them into a wall or off a cliff. Which is everything except dragons, giants and mammoths.

There was a point in the game where I quit using them altogether. I think I might have frost breath as fav/equipped. I have the nightingale ones as well, haven't even touched them..I forgot all about the Nord one that can be used as well.

I liked being able to freeze AOE some of the mobs in dungeons. (if I screwed up and was detected)

With no way to track the development of shout leveling I gave up on trying to improve them.

KILL has its uses!

Marked For Death is pretty awesome.

Pretty much this, Ice form is also great and slow time for a pure mage is really not fair.

I found marked for death and ice form to be the most useful. Ice form when facing multiple enemies that deal a lot of damage. Get them all with one shout and you can kill them one at a time while the others remain frozen on the ground. And marked for death for strong single enemies like dragons and dragon priests. Hit an elder dragon 3 or 4 times with it and he will die from like 2-4 sword hits on master. First I thought the shout was nearly useless since I could not see any visible reduction of their HP, it reduced the absolute amount of HP, not the percentage.

I was lol the first time I tried to use...wtf is name of the shout...makes you attack faster etc. etc. I got script in the top left "your current weapon equipped is already enchanted"

I thought to myself, "well, not wasting any more souls on this one." lol.

I just remembered that you can meditate on the fire breath shout, but you are obligated to join the companions to get one of the words. Oh and calling a dragon is always cool right?

Actually with 3 words in Unrelenting Force you can even kill giants by throwing them down hills (just killed two like this). So the only creatures this doesn't seem to take down is Dragons and Mammoths.