On the subject of vocals, l can enjoy recordings that have "flawed" performances that feature voices that possess distinctive qualities or convey emotion with particular intensity. 60s folk artist Karen Dalton for example sings in a very heartfelt, down home type of way that I find particularly intoxicating in its honesty. On the other hand the blackened shrieks from Keiji Haino are movingly raw and intense. I've always found the voice of David Thomas, the frontman of Pere Ubu, to be likable in some way I can't quite explain. It has this manic energy to it. Similarly, Scott Walker puts on quite a performance using his voice, something that taps into kitsch in a way that makes him more disturbing than any metal band's growling frontman.
Then some voices are just appealing or intriguing. Some voices quicken the heart. Curtis Mayfield and Baby Huey have such soulfulness, such musicality, and such inspiring power behind them. The self-titled Curtis album in particular is definitely one of those desert island picks. Nico on the other hand has a subtler power, this almost mystical pastoral quality to her singing; it seems natural that she should go on to do something so archaic as The Marble Index, a [anti] pop album that somehow came from the middle ages. I also find Siouxsie Sioux and her spiritual successor Zola Jesus have a really 'strong' vocal presence. Really, I have a thing for lower pitched female voices. On the opposite end of the spectrum however Hope Sandoval purrs with such warm seduction I can't help but be caught up in her spell. I could listen to her all day. That's something I couldn't say about Kate Bush, but overall her voice moves me even more oddly enough. Michael Gira of Swans fame is the same way.
With some vocal performances it's the actual performance and range therein. David Tibet arranges and enunciates words in such a way as to turn a music track into a ritual. Miranda July literally puts on a show. A lot of hip hop and rap amounts to vocal acrobatics and rhythmic flow, and to that end I consider Rappin' Ron & Ant Diddley Dog to be the best of the best.
Some more recent artists whose voices really catch my ear include the above-cited Zola Jesus, Tyler the Creator with his raspy gnarled growl, Abel Tesfaye aka The Weekend who can channel Michael Jackson to an eerie extent, and King Krule who---despite being something like 19 years old and looking like Ron Howard---manages to sound like a weary undead blues singer.