Of the bands you've listed, Symphony X is the one I'd try first.
My favorite albums are the last two ... Paradise Lost and Iconoclast. Iconoclast is about the world being taken over by robots...doesn't get awesomer than that. I saw them earlier this year and essentially heard songs from both those 2 CDs. Michael Romeo (guitar) is amazing.
I have picked up the most recent CD's from Primordial, Serenity, Kingcrow, Mayan, and Redemption.
So far, not super impressed. Primordial's one song "no grave deep enough" is the only song I have liked by them so far, mostly due to their questionable lyrics (IMO of course)
I cannot seem to get into Kingcrow. Kind of Alice in Chainsy? Need to listen more.
Serenity is growing on me, but not fast. I think it's the accent, which normally isnt a problem..."New Horizons" is good.
Redemption's CD I think is pretty good. It has taken a few listens, but I like most of the songs, in particular Noonday Devil and Dreams From the Pit.
Mayan sounds like Epica, sans choirs/orchestrations, sans simone (she is on some of the songs). Just brutal.
I've been going to Last.Fm and finding all the band's recent live setlists (if they have them) and making playlist from those. You may want to check out Kamelots...they have added a couple of new songs ("Sacrimony" and "Season's End") from the upcoming album which you can either choose to partake of now or in person later
Everybody else I have not checked out.