Or are they more for RP purposes? Why use Dawnbreaker when I could use an enchanted Dragonbone Sword?

haha, that's funny. Good one buddy, i see what you did there.

(yes the daedric artifacts are useful: Mehrunes Razor, and Sanguines Rose... 'nuff said)

Seconded.

Dawnbreaker is awesome, especially when going into ruins. Also it just looks wicked.

I use Volendrung. Technically I can make a daedric warhammer to do more damage, but it's already viable to me on legendary so....not sure what else to ask for really

Ah yes, Volendrung.....the bandit chief tenderiser.

The Ring of Namira is useful, especially at low levels.
(+50 Stamina)

dont forget.............. The wabbajack

Because you don't want to use a dozen perks up on enchanting and smithing?

Let's add Azura's Star/Black Star to that, too.

And the Sanguine Rose for Dremora Lords.