Masterwork is debatable, depending on who you ask. Just with anything. *Deep intake of breath*
The self titled album pretty much sucked. There's some great songs, but Gene Adams (first singer) is... well, the Rod Tyler of the band's history. Couldn't sing to save his life. Next album, Night of the Stormrider, featured John Greeley on vocals, and he had a much less aggressive approach to his vocals than the next singer (the Almighty Matt Barlow). I'd say Stormrider is my favorite album by far despite not having Barlow on vocals. His (John Greeley)'s voice gets the job done and the album just rules. In fact, that's the album Angel's Holocaust comes from. Matt does some great versions of those too, and you may be listening to a version with Matt on vocals, but i'll get to that soon...
Enter Barlow era. Burnt Offerings was his first album with the band, and was very dark. Jon Schaffer (band mainman and the only dude who's really in the band) doesn't like it because he says he was in a bad place while writing it, plus he was trying to write all epics (as pretty much all Iced Earth songs had been historically), but there's some amazing tracks on there such as Dante's Inferno (their major epic, just over 16 minutes long), Creator Failure and the title track, Burnt Offerings. Fans are mixed in this one, but it's a strong album and very, very good.
Dark Saga comes next. This is where Jon discovered "straightforward" songwriting, and in my opinion the album is only saved by Barlow's vocals, since there's some pretty boring riffs. Still, the songs are good and the concept (based on Spawn) is pretty solid, and the album undisputedly reaches its peak at the climax of the story with the song "A Question of Heaven", an incredibly emotional song. This album has plenty of highlights though, just not really a "strong" album like the second and third were.
Next up is Days of Purgatory, basically an Iced Earth cover album. They basically had Barlow sing over the old songs, covering a good portion of the first two albums and offering alternate versions of some songs from Burnt Offerings. Really a great compilation album. Then came Something Wicked This Way Comes, the album that seems to be most highly regarded since it was the one that gave them the biggest push in exposure up to that point, and many fans had their first taste of IE this way. It has some good songs, lots of filler, but it also has the Something Wicket trilogy at the end, which rivals the greatness of Dante's Inferno. At this point Jon said he was going to do a Something Wicked concept album when the time came.
Next up is Horror Show, Jon's concept album where each song is based on a horror movie (except Ghost of Freedom, but it's scary how shitty that song is so it fits perfectly). Highlighs here are Wolf, Damien, Phantom Opera Ghost and Dracula, though Dragon's Child and Frankenstein are both amazing songs as well. Then came their cover album, which really holds no merit other than to show how diverse Barlow's range is. Decent, but not worth it.
Then Barlow left and Tim "Ripper" Owens entered the picture to do The Glorious Burden, Jon's war/history themed album. You may remember from Priest's two shittiest albums, Jugulator and Demolition (though that was of no fault of Tim. He emulated Halford perfectly, they just wrote shit songs for him). The Glorious Burden is pretty fucking awful, and goes to show that Ripper doesn't fit with Iced Earth's sound (this is heavily debated, but for real fans there's only one singer). It's not a wasted effort, as parts of Gettysburg are pretty amazing, but it is too ambitious. Gettysburg is Jon's intentional attempt at an epic that is 30 minutes in length, and has about 10 minutes of really great material.
Then Jon had to go and piss in everyone's faces not only by allowing Ripper to sing on the Something Wicked Concept which had been anticipated, but with Barlow on vocals, but he also re-recorded the fantastic Something Wicked trilogy with Ripper on vocals. Not only did Ripper fuck up Prophecy and The Coming Curse (Birth of the Wicked was bad, but not the abortion that the other two were), but Jon actually re-wrote parts of the song which sound absolutely terrible. Then Jon wrote another shitty album for Ripper to massacre even further, which just happened to be part 1 of the something wicked concept.
I'm not biased at all am i?
Now Barlow's back. That brings you up to speed. Any furhter clarification can be given if asked