We all know that "+ resistance to all" is the most important stat to master inferno difficulty. But are there single items that really matter?
I think so, and here are some initial ideas:

1. The expensive one:
http://eu.battle.net/d3/en/item/string-of-ears
The flat melee-dmg migration will really change your game. I was able to buy a -14% belt, and it was worth every piece of gold.

2. The cheap one:
Shield with high %-Blockchance and high amount of Block. Ignore the rest of the stats!

b3chhfy6.jpg

This item may look inferior at first sight, but if you compare the "white" numbers against other shields you will easily understand. The 28% chance to block and the high amount of damage blocked result into an absolutely great dmg-migration ingame. Plus, these items are cheep to buy in the auction house.

Greetings,
Youngtimer

PS: IŽd like to see what items you have found that helped you through inferno.