Better at what? Holding aggro, doing damage, taking damage, moving slightly faster than a tortoise with a limp? 
First two - I'm not sure these two classes of Tanks are meant to do the other two 
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In that case I would favour the Ice/Stone guy.
If it has eyes, you can blind it, if it has blood, you can make it bleed, if it has a mouth, you can make it scream.
Stone/Ice will have very high survivability, but pants damage.
Ice/Stone will be fairly well balanced.
Stone/ice is imho the toughest tanks around. Massive resist/defence added up with icepatch and you can survive really really alot (ok.. ranged psi is still worry).
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Sure, but given the fact that DreamWeaver asked for a tank with good aggro control and high damage output Stone/Ice is not really an option as it fits only half the bill while Ice/Stone should provide both without much of a problem.
If it has eyes, you can blind it, if it has blood, you can make it bleed, if it has a mouth, you can make it scream.
I used to have a 28 stone/ice, the damage output wasnt really that bad.
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Damage would have gone down a fair bit when using Granite however. And if you don't use granite then you get better defence with Ice. Tremor and Fault are also very good damage mitigation powers.
Buddy of mine has a concept for a Tanker toon they want to try out, but which is better - Stone with Ice Melee or Ice with Stone Melee?
Is it time for the dance of joy yet?