1) Slayer - Show No Mercy
2) Judas Priest - Painkiller
3) Anthrax - State of Euphoria
4) Damageplan - New Found Power (Dimebag Darrell's final album)
5) Ozzy Osbourne - No Rest for the Wicked (how this one's even on my list is beyond me, especially since it's the recording debut of Zakk Wylde)
My dad and I both had copies of No Rest for the Wicked. My dad got the original release on cassette at a flea market about a year after getting me the 1995 reissue on CD for Chrimbus. Hero was on both releases, and on both releases, the track was NOT listed, leading me to believe that the song was titled "Fools No More". Funny thing is that it was my favorite track on the album.
The whole Tony Martin era of Black Sabbath is super underrated. But Priest's Painkiller? That's overrated, if anything. If I'm thinking of underrated then it's was either panned by critics, didn't sell very well, or fans of the band deem it to be a weak release. I would have to really think about my choices though.