Into eternity are definately the lesser of the three, I've never really like opeth that much though to be honest.
I just realised that there's been barely any mention of black metal in this thread! Some recommendations for lesser known banRAB:
Abigor - Nachthymnen + Orkblut are both absolute BM classics. Classicly structured black metal that is highly intricate, highly fast and highly good!
Blut aus nord - Everything these guys have put out is great. There latest release, The Work Which Transforms God, is extremely unique. It's very weird, droning BM that is quite difficult to wrap your head around.
Dark tribe - In jeraspunta - Extremely harsh and intense BM, not for the faint of heart!
Falkenbach - Folk infleunced BM, everything these guys have done is freaking great.
Varathron - His majesty at the swamp - Very thrashy and very good BM.
On a non black metal note, Transcendence into the peripheral by Disembowelment (death/doom) is probably the darkest, most brutal metal album ever created.