I thought I might post my build since I've been having good times rolling with this, and haven't come across an Elite/Champion combination I could not down yet save for when I was in one of the Kulle dungeons in Act 2 Hell with an Elite 'Big guy' (can't quite remember the name) with Immune Minions, Knockback, and Vortex.
The reason I am posting this when so many other threads exist is also because while other builds work, I've had some problems facing certain combinations of affixes with them that I don't have with this build. That's not to say this build can take everything. I think the major "thing"(it could be a problem or a feature) with most builds is that it's not a skeleton key. So sometimes they work and sometimes they don't.
The basis for this build also is not requiring very specific(not to mention sometimes exceedingly costly) gear. I'll list 3 examples of current builds on the forums that have seen much success but I haven't been able to make work as well.
First off, my build;
i.e. Molten, Plagued, Fire Chains, Arcane Enchanted, Waller, Jailer, Teleport, Vortex, Fast, Illusionist, Extra Health, Frozen, Knockback.
The only known issues I have with this build is when I'm facing;
Immune Minions - If I can't do damage with Magic Missile, I can't slow nor get back AP. And sometimes the elite doesn't cluster with his minions so my Arcane Orb doesn't hit him either.
My usual 'rotation' is to first spam Arcane Orb til' I have no more AP(can get off about 5), kite and shoot MM, and use AO whenever possible. I only use Diamond Skin if I get trapped(i.e. walled-in, jailed) OR to regen AP faster by tanking them for 5 seconds.
Items required, not much. High vit, low vit doesn't quite matter. Although I am slowly speccing towards lower and lower vit. The main weapon ought to be either a 1h dagger, sword or wand. Fast attack speed is crucial since you're not channelling anything, and it makes a huge difference in firing off MMs or AOs while kiting. Don't believe me? Try it with a 1.25 aps 2h and a 1.60 aps 1h. There is almost no delay when firing with a fast 1h.