Starting out in Wrath (warrior tank)
Edit 10/8/08: Cleaned it up. Added some items from Thinktank and ranked items on the list according to defense. This is now an uncrittable gear list.
Thinktank: WotLK - getting uncrittable
Level 80 ratings
Demog's Tank Gear List
A few other things to note is that I have not tested any of this actually leveling up, but with one of the premade 80s and I have played exclusively warrior...so I can't vouch for pallies, DKs, or our bear cousins.
My beta warrior has around 514 defense and 100 resilience and is slightly above the uncrittable threshold. To date he only has one heroic drop (his cloak), no emblem gear, and no crafted gear.
Obviously, as xav and many others have noted, you're going to need a lot more defense to hit uncrittable as a warrior. And that amount is only going to increase as you level up to 80. So throw on enough defense to hit uncrittable and check it every time you ding.
The two factions you want to worry about are the wyrmrest Accord and Kirin'Tor. Wyrmrest first then Kirin'tor if desired.
Uncrittable Gear list (items ranked according to defense):
1.) Cloak of Peaceful Resolutions
2.) Cloak of the Enemy
1.) Sabatons of Draconic Vigor
2.) Slaughterhouse Sabatons
1.) Duanting legplates
2.) Iron Colossus Legplates
1.) Duanting Handguards
2.) Fireproven guantlets
3.) Expelling Guantlets
1.) Breastplate of the Solemn Counsil
2.) Silver-Plated Battlechest
1.) Dragonflight Great-Ring
2.) Gal'darah's Signet
3.) Solid Platinum Band
1.) Tempered Saronite Belt
2.) Girdle of Obscuring
1.) Tempered Saronite Bracers
2.) Bracers of Reverence
1.) Tempered Saronite Helm
2.)Helm of the Ley-Guardian
Burning Skull Pendant dropped in gun'drak for me
Armor Plated Combat Shotgun
1.) Seal of the Pantheon
2.) Dabiri's Enigma (insert pre-wrath def trink here)
1.) Titansteel Shield Wall
2.) Leeka's Shield
Cloudstrider's Waraxe from heroic oculus
Eternally Folded Blade
Cresent of Brooding Fury
(whichever is easier for you)
1.) Pauldrons of Reconnaissance
2.)Crusader's Square Pauldrons
If my math is correct, going with the highest def gear (aside from the wep, I used Cresent of Brooding Fury) you will obtain +178.51 defense skill. Which brings your total defense skill up to (400+178.51)=578.51
Which brings you 38.51 points over the uncrittable threshold. Plenty of room to swap gear around and still remain uncrittable. All this gear is obtainable through quests, regular instances, or gathering mats. You don't even have to venture into a heroic or a raid for any of it.
(I believe the only pieces here unattainable till level 80 are the legs and the pvp stuff. The rep gear will be hard to snag pre 80 unless you are into running level 80 instances pre level 80. It should be possible to have nearly this entire set by level 78.)
The only other wrath defense trinket besides pantheon is in raid content.