My favored class (and the one I'm playing right now) is the 2-handed warrior w/ the Champion Specialization. He deals out a ton of damage and is great for taking out mobs of enemies. As with any character build, choosing the right skills and crafting the right equipment will make your life easier. Build up Con & Str with both skills & equipment. Look for skills & mods for your weapons/armor that give you guard. You need to keep that guard bar high because you will get hit a lot. I also like to carry selection of "creature specific" weapons. One with a dragon rune for dragon fights, one with a demon rune for closing rifts, and so on. Also try to buff up your critical chance to hit and your critical damage.
My second choice, though I've never played one, would be a one-handed weapon shield warrior. I always have either Blackwall or Cassandra in my party and they take a ton of damage and never die.
By choosing the 2-handed warrior means I rarely take Iron Bull with me as our skills overlap too much. I always have a mage, usually Solas or Dorrian, and a thief, usually Varrick but sometimes Sara.
This is just how I play, I know a lot of players love to play as a mage, but I've always been more of a weapons/melee type of player.