...yet none of their riffs have been copied from Metallica. I cannot think of a single Trivium riff that could be classified as a "generic metallica copycat riff".
And if they want to be as big as Metallica then fair play to them, there's nothing wrong with having ambition.

I've heard people say that. I don't share the same views.

definitely the crusade

Yeah the crusade is deffinatly the most technical song on the album

The Crusade isn't thrash. Trivium doesn't steal any Metallica riffs (Well ok, Unrepentant comes to my mind right now), they don't even sound like Metallica (even if there are some rumours goin round that Matt's trying to sound like Hetfield in his 90s. ). They kinda have their own riff style in my opinion, even the Ember/Ascendancy riffs didn't sound like every other metalcore riff to me, they had something special that made me love them I guess.
The Crusade now doesn't have as much of those riffs for me. It's got fuckin' bad songs as The Anthem or The Rising, but it has also fuckin bad ass songs like the titlesong (though I expected more from a self titled 10 minute epic fuckin' instrumental...), the awesome first 3 tracks and something like To The Rats and Becoming the Dragon ( which was really awesome to hear live, didn't expect it!). A good album, really. But way to hyped before the release, I just remember listening to the record the first time and being really, really disappointed... oO
Well, anyways... some good thrash bands:
Destruction (best german thrash ever)
Exodus
Megadeth
Testament
Fueled by Fire (really cool young band)
maybe even Anacrusis
Heathen
old Metallica (definately thrash imo)
Flotsam & Jetsam

And the most technical song... I don't know... Contempt? titlesong?

For me, I'd say The Crusade and Contempt are most definitely tied as far as techinicallity are concerned.