I've been using the Elite Knight set and a Black Knight Shield for most of the game. It seems a superior "standard armour" choice to anything else I discovered. Recently I uncovered first the Black Iron set and then Havel's Set.
None of my armour or shields are currently upgraded. I'm playing a melee pyromancer build, wielding a Claymore (and occasionally a Silver Knight Spear). Strength is about 20, Dex about 25 and Endurance about 35. Been wearing Havel's ring since I found it. I can't say as I've noticed a particular speed difference between the sets, but that might just be me being dumb.
At the Anor Londo Blacksmith, and feeling like I should finally upgrade some armour. Which set should I go for, and what shield(s) to go with it for general-purpose wear? Answers I've seen elsewhere seem to be terribly conflicting.
Best Answer
Armour
At full upgrade, (+10) the Elite Knight's Set has:
The Black Iron Set fully upgraded (+5) has:
The difference is big enough to decide one or the other, though while the Elite Knight Set is lacking in defence vs. Black Iron Set, it still has a fairly high defence and poise stat for it's class (Medium Armour). The Black Iron set however, being a Heavy Armour set, while still impressive, it is Heavy Armour, so it's to be expected.
Now we come to Havel's Set. This is Heavy Armour, is incredibly heavy, and it can't be upgraded, but the stats make up for it:
The poise alone is impressive enough. There is very little that can stagger you with poise that high. However, the major downsides are the weight, and the lack of upgradability.
Shields
You have a few choices, depending on how you choose to play.
Firstly the Black Knight's Shield. This shield, while heavy, does have a very high Fire resistance (which can come in handy a lot in this game). Unfortunately, the only thing that changes during upgrade however, is the shield's stability (how much stamina damage is dealt per block)
Then there's the Grass Crest Shield. This shield has a nice little effect that boosts stamina regen. However, this comes at a price - a reduced physical defence.
Now we have some Greatshields. The first one is Artorias' Greatshield, which has a nice little effect that blocks status effects, like poison and toxic (doesn't work for residual effects like Blighttown poison swamp, or in PvP). This is actually made from a boss soul, which can be made when you meet the Giant Blacksmith
And finally, Havel's Greatshield. Unlike the armour set, this can be upgraded, but again, like Artorias' Greatshiled, it makes little difference in the stats. It does however, when using the "Heavy Attack" two handed, will cause a temporary boost of poise and defence.
I hope this has been enough information for you to compare, but it all depends on your fighting style, and how you want to play the game.