Yeah Judas Priest is awesome, and used to be my fave. Rob's own band by his name Halford is also very good. I can't believe the pitch he can reach with his screams at his age. Bruce Dickinson also has a pretty strong voice for his age.
At one point Metallica was my fave, but they lack the creativity I look for, and I couldn't stand St Anger.
Nowadays Tool is my fave band, but they're really more Alt/Prog Rock than hard rock, though they
can jam hard.
One song by Halford that really struck deep with me when I first heard it was Silent Screams. I happened to be playing F.E.A.R. at the time, and it seemed to fit perfectly with a mission called Bad Water I was playing. The lyrics are also very relative to what's going on in the world today.
Sorry if the audio dubbing is off putting. I was going through a phase where I wanted to have both visual effects and humor in my videos. It's just a short part at the start though. This is best viewed in YouTube's small viewer size, due to the res it was captured at back then.