On the heels of having had, shall we say, "lively" discussions with Master Looters over whether two belts were "best for healers. healers get first priority" in Ulduar in the past two weeks (once in 25 the other in 10), I realized the best defense is an offense. These discussions go a lot more smoothly when you can point to unbiased third parties and say "um, no."
I'm not a math geek so I am not going to argue BiS (best in Slot) with the maths here. Rather, I am going to discuss your gearing up opportunities by boss, to help you prep your wish list. If you want to see BiS across all available 10-man and 25-man raids, including Ulduar hard mode boss drops, shadowpriest.com has an excellent list. With more math than you can shake a stick at.
Words of Caution: Much of the Ulduar loot lacks hit. So don't be quick to shard or sell your existing gear when you receive an upgrade. You may have to swap gear around for raids to ensure you stay hit capped.
The list, after the break.
Flame Leviathan
a.k.a. the Roomba Boss.
Even guilds who are not ready for Ulduar can come in here and tap this pinata thanks to this being a vehicle boss.
- Combustion Bracers. Even if you are hit capped now, these bracers are good to have in your back pocket for the next time you get a great upgrade that tosses you back down below the 289 hit cap (with 6 points between Shadow Focus and Misery.)
- Lifespark Visage. A model re-used throughout Ulduar. Makes you look like a cowboy who won a shiny medal of some sort. Thankfully, we have the ability to hide our hats.
Razorscale
Many guilds skip over Razorscale as she's an optional boss, which may make these items harder to come by.
- Binding of the Dragon Matriarch. An excellent spellcaster belt. It lacks hit however, and lots of folks are unclear on who can use spirit other than tree druids and holy priests, so be ready for arguments it should go to a healer first over you.
- Eye of the Broodmother. A nice upgrade to swap out for your existing crit trinket.
XT-002 Deconstructor
- Conductive Cord. Another belt, not quite as good as the one from Razorscale if you are looking for crit, but you'll likely have more shots at this one.
- Plasma Foil. Your first shot at a weapon upgrade is this dagger. Better than KT's 10-man spellcaster mainhand, but not as good as the KT Heroic Torch of Holy Fire (a case wherein the healer weapon was better than the other similarly available dps weapons.)
Ignis the Furnace Master
- Igniter Rod. You want this offhand. Burn DKP if you have to. Considered #3 Best-in-Slot by shadowpriest.com and offers a significaint upgrade even over Nax 25 offhands.
- If it would be sharded otherwise and you are still rocking a blue cloak, grab the Shawl of the Caretaker. Otherwise, play nice and just say no. Its haste and MP5 make this a healer upgrade.
Assembly of Iron
- Lady Maye's Sapphire Ring. The points for haste could be better spent elsewhere, but likely a solid upgrade unless you have the Lost Jewel from Heroic Naxx.
- Runetouch Handwraps. These bracers, with spellpower and crit, unlike the ones with hit from Flame Leviathon, are also good for healing priests as well, so expect some competition.
- Stormtip. Stat-wise very close to the Plasma Foil, but with less-desireable haste.
Kologarn
(Cache of Living Stone holds his loot)
- Emerald Signet Ring. Another good hit piece to keep in the bank to swap in/out as needed.
- Pendant of the Piercing Glare. With hit and haste, stam and int, this swiss army knife necklace is not the best choice for anyone, but if you need another hit piece to keep in the bank…
- If it would be sharded otherwise you can grab the Spark of Hope trinket, but it's targeted for holy priests and resto druids.
Auriaya
- Elemental Focus Stone. If you need a quick hit fix this trinket fits the bill. However the Sundial of the Exiled badge trinket is still considered to be far superior, as is the Embrace of the Spider from Naxx 10.
- Mantle of the Preserver. OMG pretty spellcaster shoulders??? Solid upgrade for your 10 man gear, and a shade better than the 7.5 shoulders overall.
- Nurturing Touch. Your best wand upgrade unless you do Freya hard mode.
- Raiments of the Corrupted. Think of this as your new Ebonweave Robe.
Mimiron
(Cache of Innovation contains his loot)
- Static Charge Handwraps. Gloves, unlike the handwraps from Assembly of Iron. Grab them only if you need the hit.
- Valorous Circlet of Sanctification. This tier piece is second only to the Heroic Ulduar set piece.
- If it would be sharded otherwise you can grab the Pulse Baton. The two previous main hands are much bigger upgrades for you.
Thorim
(Cache of Storms holds his loot)
- Valorous Mantle of Sanctification. Tier shoulders. Upgrade for 10 man Ulduar and 25 man Naxx items. And best shoulders you can land until hard mode 10-man or 25-man Yogg-Saron.
- Handwraps of Resonance. More gloves, because there haven't been nearly enough gloves so far…
- Leggings of Unstable Discharge. These will be an upgrade for those who don't have 25-man Naxx tier pants (which are only a shade better.)
Hodir
(Cache of Winter holds his loot)
- Valorous Pants of Sanctification. Your Tier 8 pants. Decent upgrade. Some opt for the healer version of the pants due to their increased spellpower.
Freya
(Freya's Gift holds her loot)
- Valorous Handwraps of Sanctification. Tier gloves, and your best upgrade for this slot in here.
- Unraveling Reach. Ultimately, a main hand/ off-hand combination will give you better dps. But if you need hit on your weapon and have not had good luck in the off-hand department, you can grab this.
General Vezax
(Is it just me who wonders if he is General Rajaxx's long-lost cousin?)
- Underworld Mantle. Your best shoulders in this instance.
- If it would be sharded otherwise you can grab the Pendant of Endless Despair. But you probably have better.
- Vestments of the Piercing Light are your second best Ulduar 10 robes, with Yogg-Saron's tier robes the best.
Yogg-Saron
- Valorous Raiments of Sanctification. The tier chestpiece is your best in slot item from this instance.
- Devotion. The 487 spellpower and its shininess may convert some folks to staves, at least for a while.
- Treads of the Dragon Council. Finally some boots! Your only option from this instance.
Algalon the Observer
(gift of the Observer holds his loot)
- Pulsar Gloves. Best 10-man Ulduar gloves.
- Starlight Treads. Best 10-man Ulduar feet.
- Nebula Band. Best 10-man Ulduar ring.
- Drape of the Messenger. Good cloak if you still need items to swap in/out for hit.
- Meteorite Crystal. Not an upgrade for you. If it will otherwise be sharded, take it for your healing set.
Trash Drops
- Drape of the Spellweaver. A good cloak upgrade.
- Iceshear Mantle. Another shoulder upgrade option.