The most powerful armor is either T-51b Power Armor or Tesla Power Armor because it has the highest Damage Resistance.
If you're looking for anything else, there are other armors and clothes to test out.
UPDATE : With the Broken steel downloaded the best armor now is Enclave hellfire armor with a DM of 50 and 10 for the helmet.it also has no agility penalty. if u dont wear power armor for some reason the best option would propably be either lag bolt's combat armor or ranger armor, depending on what u prefer.
It all depends on how you are defining powerful. In terms of pure damage resistance the T-51b offers a 50 damage resistance. However it offers very little else. The Tesla armor has a damage resistance of 43, but it weighs in 5 pounds heavier than the T-51b armor. It does however offer a +10 to your energy weapons skill.
Overall the best armor in the game when comparing damage resistance to weight is the Ranger Battle armor. It has a damage resistance of 39 yet a weight of only 27 pounds. However the value of the ranger armor is mostly measured in its benefits. It adds +5 to your action points. If you use VATS that helps out a good deal. It also gives you a +10 to your small guns skill. But most importantly it gives you +1 to luck. Most people under estimate luck in this game. Luck affects everything you do! From your odds of finding a Nuka-cola quantum in a vending machine to scoring a critical on that head shot, the higher your luck the better your odds. In terms of measuring damage resistance to weight ratio and its added effects the Ranger Battle armor quickly wins out as the most powerful.
If you have the Broken Steel add-on a couple of new options are added. In the power armor category you have the Enclave Hellfire armor and in the more traditional armor category you have Lag-Bolt’s combat armor. The hellfire armor offers 50 damage resistance, same as the T-51b and also weighs in at 40 pounds. It also offers a +30 to fire resistance, but that only really comes into play against fire weapons. (which in all actuality is other hellfire troopers)
Lag-Bolt’s armor gives you a damage resistance of 38 with a weight of 30. Plus it offers a full +10 to action points, which if you use VATS often you know is almost immeasurable in terms of added usefulness. Lastly it adds +10 to the big guns skill, however by the time you find this armor in the game you most likely have your big guns skill to 100 anyway. (If you’re a big guns user that is)
However all this is dependant on your style of game play and your skill. If you don’t use VATS and you’re finding yourself getting your ass handed to you in battle then you may very well find the extra 11 points of damage resistance helpful despite the added weight. If that’s the case then by all means use one of the power armor options. One thing to consider is that you can mix and match armor and helmets. As you go through the game you will notice that no matter what armor you wear your helmet wears out considerably faster than your armor. This is due in part to the fact that the enemy, like you, is aiming for your head! There is nothing saying you cant wear one of the power armor helmets with the ranger Battle armor or any other combination.
One last thing to consider is that effects offered by armor like +10 to energy weapons or small/big guns only plays a part if your skill in that category is below 100. Contrary to what some would have you believe there is no additional benefit to raising a skill above 100. This also applies to effects that raise your SPECIAL attributes. Anything above 10 has no additional benefit. ReapTheChaos 20:20, January 29, 2010 (UTC)