Either sell them or throw them in the river.
They're useless and not as powerful as my current weapons.
Usually I disenchant the ones I can, the rest I sell or drop in a chest.
I put all the coolest unique weapons in my display cases, but the rest I put in a chest in my house.
I like looking through all my unique armor/weapons from time to time so I keep all of them in a chest.
Also, I have a room full of cheesewheels...
I put the Daedric artifacts and the other unique weapons in the strongbox next to my bed on the second floor of my house Lakeview Manor. If that steward Rayya touches them, she's toast.