He gets me every time. Is there an effective way to avoid getting hooked by him?
There are multiple ways to avoid his hook.
Once he shows his initial hook animation (pointing), you have to run in a circle fashion around him. Do not run away, as the hook can catch you easily this way.
Another way to avoid the chain is to keep the butcher at maximum distance, he has to be off screen. When he throws his hook it will not reach you. A good way to practice this is to run down as soon as the fight starts, as he usually begins with hook. Then shoot him from the distance. This is only viable if you deal ranged damage. This works fine as the only other attack that can kill you is his charge and he spits fire just before that.
Note: The chain deals about 30k damage on Inferno, so either you go for a quick death, dealing mass Damage (30k+) or you get at least 30k vitality and some good armor. But even with 30k health he will oneshot you with his other abilities.
Many people claim you can kill the Butcher with about 15-17k damage before the enrage timer is activated, but this works only if you deal constant damage (like a tank). For a Demonhunter you need about 20k damage without Sharpshooter and still you will die very often.
Stand next to him and kill him quickly.
The achievement "Don't Stand in the Fire" required me to avoid getting hooked when fighting the Butcher on Hell difficulty. So I cranked my DPS up to 30k, turned on Frost Nova with reduced cool down and tanked him as a 60 Wizard.
Granted, this is not great advice in general and won't work on Inferno, but in order to get the achievement, I had success being as fast as possible.