This is the result of a current bug in the way Diablo III Handles Attack Speed enchants, as of version 1.0.1.9558. Essentially, there are two different enchants that increase attack speed, which work slightly differently.
The first kind, which displays on tooltips as Increases Attack Speed by x, is supposed to only show up on weapons. When this Affix is on a weapon, it increases the attack speed of that weapon, but it does not increase the speed of your other weapon if dual wielding. Most importantly, if this verbiage is found an item other than a weapon, it does nothing at all.
The second kind displays it's tooltip as Attack Speed Increased by x. This affix applies it's modifier globally, and will always work, no matter what item it's on. If this affix is found on a weapon, it will even apply to your other weapon while dual wielding.
This is slated to be fixed in patch 1.0.3.
Helmets:
The Helm of Command These will be the BiS for barbs and most likely monks due to the rolls of %life, % block, res All and Dex/Vit/Str.
Mempo of Twilight will be a PvPer helmet due to its high percent of cc reduction, % life, and attack speed.
Andariel's Visage is one of the most widely used helmets in the game at the moment. High attack speed and crit chance + chance for a socket, % life, and high base stat.
Chest:
Tyrael's Might Chest with movement speed (movespeed) increase and damage increase to elites.
Beckon Sail Top chestpiece for Demon hunters due to high Increased Attack Speed (IAS) and crit chance increase. Can roll 0-3 sockets for huge Dexterity bonus.
Tal Rasha's Guardianship IAS on chest and a set bonus of (2) 3% increased fire damage, (3) 3% increased lightning damage, and (4) 3% increased cold damage.
Pants:
Inna's Glory IAS, movespeed, and crit chance.
Jewelry:
Justice Lantern for extra %block.
Natalya's Mark IAS + high base stat rolls and use of Set bonus.
Flavor of Time like OP stated IAS, movespeed, and CC reduction on a neck. PvP neck for sure.
Mara's Kaleidoscope decent tank neck with reduction from melee/ranged.
Off hands:
Storm Shield for the % reduced damage.
Ivory Tower is another decent shield that can be used for its damage reduction and its chance at high % life.
Black Bone Arrows for % damage against elites will make farming quicker for DH.
Dead Man's Legacy is another quiver. This differs from black bone in the fact that it can give % increase to some of DH strongest abilities along with a chance for the highest % attack speed on quiver.
Uhkapian Serpent is BiS for WD due to its chance at max off hand damage, % damage against elites and chance on roll to give % damage to certain WD spells.
The Oculus like the WD mojo this can give specific spell % increase as well as being able to roll high Int and top damage on a source.
Belts:
String of Ears for the % melee damage reduction.
Boots:
Boj Anglers Increased attack speed and movespeed with cc reduction. These will be pvp boots in my eyes and can be fitted to any class.
Zunimassa's Journey Increased attack speed and movespeed.
Fire Walkers Reduced melee and movespeed.
Natalya's Soul Reduced melee damage and movespeed.
Bracers:
Lacuni Prowlers These are extremely powerful at the moment for an increase in movespeed to hit that 25% everyone wants and IAS which is a straight damage increase. Even better is these can proc magic properties to make them beneficial to all classes.
Weapon:
The Three Hundredth Spear, The Gidbinn, and Sunkeeper all %MF weapons for you and your Companions.
Best Answer
Here is what I found - LLL denotes low level legendary meaning it's below ilevel 60.
Rings:
Bracers:
Pants:
Chest Armor:
Amulets:
And for completeness boots here: