I think the human bonus seems the most "instant gratification" one, but I don't think it's the best one. In fact, I think all the other choices are perhaps less versatile but more useful. This fits with typical D&D style racial bonuses - humans are usually versatile, by nature, in most settings, and DA fits that.
Qunari - You're right that the 10% bonus to melee defense is less useful for archers and perhaps most mages (it's still useful for dual-wielding rogues, knight enchanter mages, and definitely any kind of warrior) but it's very useful to several builds, much moreso than an extra ability point. If you are building a tank, you're going to be tempted to at least consider a Qunari or Dwarf due to their bonuses, if you care about bonuses at all.
Dwarf - The 25% magical resistance is a huge boon. There is going to be a lot of magic damage going around if demons and mages are both potential enemies, and magic can hit at range and fly freely before your tank (if you use one) gets control of the field. The bonus is going to help a lot.
Elves - 25% ranged is also nothing to sneeze at for any class. I think I read this includes magical ranged damage (not like runes/mines, but spells flung at you from a distance) and in that case, it's almost equally useful to the Dwarf thing, though runes/mines do seem to be a thing.
Maybe you're so Boss at the game that no one but your tank will ever take damage, but I doubt that's the case for most players. The other bonuses will come in handy.