Howdy,
DeerKing, you probably don't know it, but you have asked the most loaded question that could possibly be asked on this forum!
As for the absolute best voices.... and I quote you..."any style" the best two are my wife Ruthie, and Placido Domingo. Luciano Pavarotti was up there for a long time, but Father Time has finally caught up with him. As for Ruthie, she has the credentials to prove my statement with tours of Europe, Carnegie Hall, etc. Hey, for that matter, so do I!!!!
Worst possible voice, one of the kids that sang a solo at my concert this afternoon. Hooooooeeeeee, that sounded like a mesquite thorn scratching a tin roof! Remember how you cringed when the teacher accidently rubbed their fingernail on the chalk board? I bet I'm the only choir teaching, track coaching, mule deer hunting guy in this whole state!
Coach