Often used to describe bands like Pantera and Exhorder. With mid-tempo riffs similar to those found in Thrash Metal and a tendency to focus more on groovy syncopation and heaviness than outright speed.
For national and international bands? Hate to say it, but, Katatonia. They've been great the past few times I've seen them but the first US tour was terrible. Bad sound, no stage chemistry, awkward, uncoordinated, Jonas was straining for every syllable. Glad they got their act together. The second worst has to be Cradle Of Filth, again with a combo of bad sound and substandard performance. I hear they're doing a lot better these days too. I won't judge any band too harshly over one or two bad shows, or even a bad tour, there's just so much that can go wrong.
I've been underwhelmed by a lot of big-name acts, but I think that's less to do with their performances than how the material translated or whether I even liked them to begin with. Nile played fine the two times I saw them, but I've never been a fan.
Without a doubt Marduk. Their first 4 albums are excellent and they only had a small dip during the late 90´s and early 2000´s when they kind of got stuck in Panzer Division mode for 2 or 3 albums. But luckily they have been back on track ever since "Rom 5:12" with "Frontschwein" being their crowning achievement so far. I'm also suprised i never get tired of their WW 2 topics. You'd reckon it would getting boring by some point but no. For some reason i have never seen them live though, so can't comment on their live performanc. They played about 5 times in my vicinity but each time i couldn't go due to circumstances. They are still on my band bucket list.
Dark Funeral on the other hand have a debut album which was merely okay and the superb "Where Shadows Forever Reign" but otherwise i'm absolutely bored with their ouput. It's just non stop blasting and endless tremolo's without any realy melody. I've seen 'em live twice and their live performance is just a mess. I couldn't make out one song from the other, it just sounded like one big blur of noise both times. On top of that they have a pretty goofy image that caters to all black metal stereo types. They look like how a record company A&R imagines a black metal band, totally over the top and more hilarious then scary.