From the UESP wiki, which sums up your question perfectly:
Daedra do have a penchant for extremes and are therefore capable of tremendous acts of devastation, but only Boethiah, Molag Bal, Mephala, Namira, Mehrunes Dagon and Peryite seem to take genuine pleasure in them. As Daedra are beyond mortal comprehension, they are thought incapable of being truly "good" or "evil" in the mortal sense, and for the most part, their actions and behaviors, as well as their very natures are merely interpreted by mortals as being subjectively evil, as this is how many of the infinite Daedric concepts "transliterate" into the finite mortal world.
No Daedric prince is inherently "evil". They just like to toy with the beings of Mundas.
This.
Hircine isn't "evil" he just wants friends who do stuff for him
http://www.uesp.net/wiki/Lore:Daedra