I play T.T. very often as tanks, i.e. Rammus, Cho, Voil. Very commonly so long as someone on their team doesnt get too fed, I usually end carrying or runner up carry. I build pure tank with all of them and it usually goes they can't kill me and my damage output isnt amazing compared to AD carries, but I out survive them anyway, just too tanky.

Rammus: Merc Treads, Thornmail, Sunfire, Warmogs, Abyssal Scepter
Voil: Merc Treads, Warmogs, Sunfire, Banshees, Tri. force or Frozen Mallet
AP Cho: Merc Treads/Ninja Tabi, Rod of Ages, Abyssal Scepter, Frozen Heart, Deathcap, Sunfire/Banshees/ G.A.

Personally, Cho has most damage output (if you are constantly farming), but Voil carries the hardest, but Rammus pushes best and is best in team fights, and if played right, none just really die all that much

I agree with the other guy who said it...

Renekton is a boss tank. Give him a guardian angel with that full build, and he's **** near impossible to get a kill off of.

Shyvana is good I build Tank/CC on her and jungle.

She has good mobility to escape also however isnt the most tanky champ.

Nasus would require too much farm to match the damage output of other champions and I don't think that TT is the place for him to get that.

Ryze.

olaf
hp + atamas

Shyvana got dat cray dmg output even with full tank build

I did say pure tank, not Tanky DPS. You guys are listing champions with no CC and no scaling based on defense/hp. Olaf isn't that great of a pure tank, awesome Tanky DPS though. Likewise with Shyvana.

Rammus.
Dorans Shield -> Ninja tabi -> Thornmail -> Sunfire Cape -> Warmogs -> Warmogs -> Sell Dorans -> Warmogs.

Can 1v1 any champion, I'm almost positive, I've aced fed teams, easily.

Skill order?
Q, E, W, E, E, E, E, W, W, W, W, Q, Q, Q, Q.

R when necessary, obviously.

I mentioned both Voil and Rammus, who scale off of health and armor, respectively.