I like them to have passion for what they do.
There`s different ways of expressing it. I like them to have a little arrogance and say what they think and not give a sh*t what people think of them (Stones , Oasis , Morrissey to give a couple of examples), I like them to be thoughtful about the process of the music they are making (Radiohead , Can , Talking HeaRAB) or to just give the general impression they love music & erabrace many different styles & genres (Primal Sceam , Bowie , SFA)