For those of you who are clueless about builds, here's my view on ESO builds in one simple go-go-dancing post:
Viable roles for each class for group combat--
DK: Draconic Power- Tank (Reduce both physical and magical damage, root groups and self-heal from groups.)
NB: Assassination- Physical (Melee or Bow) DPS
Sorc: Storm Calling- Ranged Magical DPS
Temp: Restoring Light- Heals
DK: Earthen Heart- Support (Control enemies and Buff party)
NB: Shadow- Self-Survival
Sorc: Dark Magic- Healer+Control
Temp: Dawn's Wrath- Support (Increase party's DPS and make the melee enemies miss a lot or the casters unable to cast.)
DK: Ardent Flame- Close-range magic DPS
NB: Siphoning- Caster DPS
Sorc: Summoning- Pets help spread incoming dmg, you keep yourself and your pets alive while also doing a bit of DPS.
Temp: Aedric Spear- Ranged and close quarters DPS hybrid.
DK should be in heavy armor for Draconic Power- with 1H&Shield. Light Armor for Earthen Heart- with a Restoration staff for more control and support and light armor for Ardent Flame- with a Destruction staff for more DPS.
NB should be in medium armor for Assassination- with a melee weapon and Shadow- with a bow. NB should be in light armor with either destro or resto staff depending on if you want more survival or more damage.
Sorc should be in light armor for all builds, using either a destro or resto staff. An exception to this would be a sneaky-healer build with medium armor and resto staff who uses Dark Exchange a lot.
Templar has the most diverse options. To heal they should use Resto staff & Light armor, to tank they should use Heavy armor & 1H/Shield, to DPS they should either use medium with 2H, DW, or Bow bars (2 out of these, 1 for each bar) for physical damage, and then use light armor and a destruction staff for magical damage.
If all of this is correct, which I think it is, then I would say that the best choice of armor (and therefore the best choice of weapons) is easy for each class.
Logically, it's as follows:
<strike>DK: Light armor, Destro-Ardent Flame + Resto-Earthen Heart.</strike>
NB: Medium Armor, DW-Assassination + Bow-Assassination.
Sorc: Light Armor, Destro-Storm Calling + Resto-Dark Magic.
Templar: Light Armor, Resto-Restoring Light + Destro-Dawn's Wrath.
The only problem with this, is that there aren't any tanks. DK make the best tanks, as they have a whole bar dedicated to it. So, instead of them playing as a close-range magic DPS or a support/healer class, I strongly would encourage all DK to be tanks. Looking at the numbers, they don't make that great of DPS or strictly support/healers anyway..either due to the need to be in melee range with light armor, or due to the lack of resources compared to other classes for casting MP based spells. Not only this, but there are already 2 classes who's best options are using Destro/Resto staves in light armor, so the gear will be much more expensive than Heavy--which will be the least desired gear.
Thusly, this is more logical for several reasons:
DK: Heavy armor, 1H&Shield-Draconic Power + 2H-Earthen Heart.
Of course this all changes when we're talking about soloing.
While soloing, the build choices are easier IMO:
Half DPS, and half control if medium or heavy armor -or- half heals if light armor.
Meaning the only good options are really:
DK: Heavy Armor + 2H with Earthen Heart and 2H abilities (Not ardent flame instead of 2H for DPS because they are spell power abilities rather than weapon power, also the MP ratio would be way off if bar#1 was still S&S.) (Since it's heavy armor--since you'll hopefully want to tank as a DK, resto-staff isn't as viable..so control+dps > heals+dps because of armor synergy.)
NB: Medium Armor + Bow with Shadow and Bow abilities. (Not Siphoning instead of Shadow, because they are spell power not weapon power and would do such low damage that it's not worth it.) (Because it's medium armor, resto staff isn't a good choice--you want that melee weapon for synergies--and this means that heals+dps isn't an option.)
Sorc: Light Armor + Resto staff with Summoner and Resto abilities. (Dark Magic with a Destro staff would be a good alternative to Summoning+Resto staff, if you prefer damage + control more than damage + healing.)
Temp: Light Armor + Destro staff with both Aedric Spear and Restoring light abilities. (Because templars have class-heals, you can just use that bar instead of a resto staff to fulfill the healing part of the DPS+Healing combo. Another option would be to use Aedric Spear + Dawn's Wrath, still with a destro staff, to control+dps instead of heal+dps.)
As far as Ultimates go, here's a really over-simplified breakdown of the ultimates:
As far as Ults go, like irons said it really depends on situations. I won't go into too much detail but this is basically the breakdown that I see:
Nova, DK Standard, Storm Atronarch, and Soul Shred are probably the best for most AOE situations.
Magma Armor, Negate Magic, Nova or Rite of Passage for defense.
Dragon Leap, Death Stroke, Overload, and Consuming Darkness are all good for specific things, Dragon Leap is one of my favorites for breaching keeps and knocking people off keep walls.
I also really like Highborn and Hitskin because they're extremely simple.
Summon Bear/Ancestral Guardian are amazing for PVE. Battlecry/Berserker Rage/Powercharge are really good.
Eye of Fear and Dragonskin I'm undecided on, they will either be really good... or not ever worth taking IMO.
Meteor and Soul Strike seem good for Spell Power builds that want a Dragon Leap that they don't need to be in the frey with, or a nice single-target damage/snare.
I LOVE Barrier as a healer/support character (the passive you get from it is nice as well.) and War Horn is also a top-notch group support ability. I think in any well-functioning group for PVP there should be at least 1 person with War Horn and 1 person with Barrier.
Dawnbreaker's probably only good for Daedra PVE.