plabonte, you have a lot of good bands in that list. In Flames is pretty good, but they seem to be headed in a bad direction with the newer stuff. I prefer Soilwork over In Flames myself for that reason, but they are very similar bands.
I like some of Rammstein's work, but some of their albums are way too techno for me. The song they did for the Vin Deisel movie was awsome and their performance in the movie kicked all that is a$$. I think it was "xXx" and the song is "Feuer Frei" if I'm not mistaken. I'd love to see these guys live!
I was unaware Amon Amarth made a music video. They're one of my favorite bands and pretty much started me on the death metal genre, and on the metal scene in general. The newest album is their best, followed by The Crusher. They are nitty gritty death metal at it's finest. If you prefer a more melodic death metal, their album "Versus the World" was also excellent. Not my favorite because it lacks the raw aggression of The Crusher and/or Fate of Norns(the newest album), but still very good.
Helloween and Gamma Ray are classics in the Power Metal genre. You'd probably also like Sonata Artica if you like them. For those who don't know, Power Metal is basically classic 80s metal with tons of keyboard work. More or less anyway.
Best concert I've ever been to:
Goatwhore, Amon Amarth, Vader, Kreator, and Nile.
Goatwhore kind of sucked, but the other 4 bands are in my top 10 list, so I enjoyed this show very much and it was worth twice the $20 ticket price!