a quick rundown of some of the best (outside of the dlc) effort set massive armor is very good, you can search it as its rather complicated to get but its all available in the deep roads and the dwarven city
juggernaut armor, I don't have this one yet so i don't know the bonuses but i know it is very good, one of the top 3 easy
Armor of the legion, Found in the dead trenches (except the shield) just search the coffins throughout, gives a bonus to damage and constitution along with being very high armor rating (tied for highest base)
Wades Massive dragon plate armor, kill the high dragon get the scale and bring it to wade in denerim, select massive and you'll get this for free, ok bonuses, high fire resistance
also if your two handed i would find the armor of diligence, heavy armor. The chest piece is found in the temple for the urn of sacred ashes quest line, the boots i found in the dwarven quest line but forget where or how (i thought it was in the dead trenches), gloves you can buy but once again forget where, no helm (which is nice so you can use whatever works). the reason why its great (i have the whole set on my rogue) is that as its heavy less fatigue and less hostility, which as a two handed you don't want it all your not the tank or shouldn't be always, but still has amazing armor (the gloves give +6) and a bonus to willpower on the set
The templar armor is alright, it's not terrible. But it's not one of the best in the game. I had it on al istair as a while until he had enough strength for juggernaut armor and it's okay but nothing special.
To be honest try to avoid massive armors they will severly hinder your Fatigue.... my 2h warrior uses the superior heavy dragon scale armor gives some stamina bonus'es and with the set on and heavy blows my fatigue is like -3% with a willpower of almost 40 i can run heavy blows berserker and have plenty of mana to use my attacks when my cooldowns are up + massive armor = more threat which means no more flanking advantage + if u play on nightmare you know what happens when your shieldless little warrior gets to many enemies on him....