pretty sure frozen orb carries itself without any need for items to help the damage. perhaps fireball and static vs immunes?

I like Bowazons, and I prefer the Strafe/FA build, especially if you find a Witchwild Bow in Nightmare.

Another one... Berserk skill barb using Howl to scare normal monsters, kill bosses instead of the Warcry barb. Way more damage output for a single attack... other than that... Frenzy barb.

You will need to run certain areas for each build, I also like the Zeal/Conviction paladin using Dream (if you can get that or an infinity wielding merc).