Opeth is soooo much better, it's like you listen to some great music but still enjoy shitty music, and go as far to some shitty band is more aggresive then 99% death/black metal bands
I always found Opeth to be boring and pretentious. One of the most overrated bands. It's not that what they're doing sucks, it's just that I have zero appreciation for whatever they're trying to do. Opeth is a band for all-black wearing college music snobs who finally found a way to openly admit to their guilty peasure (Death Metal) while still being able to pretend to be artsy and brooding and shit. Plust, their concerts have a disappropriately high female attentence rate. I'm not into getting the fucking cooties in a god damn mosh pit. That's not Death Metal. Screw that. Fuck Opeth. Seriously, fuck'em.
Currently, it's a great time to be a Death Metal fan. There have been some awesome releases in the past 18 months:
Amon Amarth - With Oden On Our Side (blew me away, might even be better than "Versus the Word" and a huge step forward from "Fate of Norns")
Krisiun - AssassiNation (never been much of a fan of the "let's blast beat till everyone is dead" subgenre, and Krisiun prolly least of all, but this one is really, really good)
Kataklysm - In the Arms of Devestation (interestingly, they toned down the blast beat crap quite a bit and the result is their best album so far, IMO. Great, great stuff.)
Illdisposed - Burn Me Wicked (just WOWOMGWTF, even better than their incredible previous effort)
Bolt Thrower - Those Once Loyal (BT are really dependable, everything they do is great but their latest one is their best since "...For Victory")
Hypocrisy - Virus (Peter Tägtgren can't do wrong, and Virus is simply another very strong Hypocrisy album)
That stuff more than makes up for In Flames going NuMetal.
Wrt MetalCore... eh, some things are not supposed to mix. The Hardcore crowd and metalheads don't go well together. I swear, if I see another "violent dancing" Bruce Lee impersonator doing his Kung Fu shit right where I am standing, I'll do something that will land me in jail. I hate those clowns.
That being said, MetalCore _is_ agressive, it's hard to beat the pure energy level of stuff like Heaven Shall Burn's album "Antigone", it punches you right in the face. But then again, HSB are probably one of the best MetalCore bands...