The top-end 2-hander weapons are the dragonbone cleaver (Witch Hunt DLC) and the chasind great maul (buy from Gorim after 3 main quests are completed). If you have the Return to Ostagar DLC, the nug crusher is an outstanding option for its early availability and massive +100 stamina boost. Some of the passive abilities in the 2-handed tree are bugged and don't work as intended. The Shattering Blows passive does not work at all, and Destroyer's armour debuff only applies on critical hits. If you're on PC, however, there is a fix to this and many other ability-related bugs.
Funnily enough, sunder arms is arguably one of the best 2h talents and puts many of the upper-tier abilities to shame, best of all being only available for one point. I don't really need to say much about indomitable, as it has no downsides to speak of; get it and never turn it off.
As for attributes, strength should be your primary focus to maximize your damage output. I don't see much use of dexterity, since your strength already contributes to how accurate your attacks are and a few paltry points added to defense isn't going to provide a very noticeable effect (assuming you already have somebody on tanking duty and they're doing their job effectively). Willpower and constitution are up to personal taste. If you find yourself wanting a bit more stamina/health, it's perfectly fine to slip the odd point into either. But I advise against sinking a significant amount into either of those because there are a number of extremely powerful items that will give you several levels worth of health and stamina (in particular, the Lifegiver ring gives you +10 constitution, the dragonbone cleaver gives you +8 willpower, Chasind maul gives 75 stamina, etc.). Not to mention that you gain a bit of both every time you level up.
Berserker is probably the obvious choice for a first specialization. The tree doesn't require a high level to quickly advance, and the Berserk sustainable costs very little in upkeep. More damage is only a good thing. Once you get the constraint passive, the stamina regeneration penalty is negated. The only thing that may annoy is that it's one of those sustainables that will automatically turn off after battle (the mod I linked earlier stops this). It seems like a perfect match for warriors who aim to deal as much damage as possible, although some don't like it. I really hate the last ability and tend to skip it. The second is up to your personal preference, although champion might be the best all around (due to war cry's powerful close range CC and Rally's great area buff). Templar has a great area stun spell but it's at the end of the tree and the three abilities before it are of questionable value in my opinion. I don't know much about reaver.
The difference between greatswords/battleaxes/mauls are the attribute and speed modifiers, critical chance, and armour penetration. The Wiki compares the different strengths of each of the weapon types