Tough choice. Do you run any unofficial patches? Because if you don't, the Mace of Molag Bal is bugged and near useless. If you do, it's a fine item and the choice gets even tougher.
Of the things you can get at your level, I'd go for Wabbajack, it's a funny tool, but it can turn against you. So does Sanguine Rose.
If you have Knights of the Nine, consider sacrificing the Masque of Clavicus Vile, because the Helm of the Crusader offers greater effects. You must have level 20 though.
Now I also see the Ebony Blade is only effective against spellcasters. While it's a nice sword, consider giving this one. You'll have to get to level 15 though.
I hope this helps. You may want to wait for other opinions or perhaps you think this makes sense after all. Remember, Daedric artifacts are among the game's most useful items, each in its own way. It just depends on your playing style which one may be less useful or less often used.