Opeth. word. i love listening their one of the calmer albums, damnation.. so beautiful.
Mikael Åkerfeldt is such talent, being able to sing death vocals and have so clean voice at same time.
Hope ends ,windowpane,
reverie/harlequin forest are my favorite songs by opeth.
Speaking of progressive metal,
agalloch, dream theater,
Riverside,
protest the hero and
Circus Maximus are also bands that are worth trying.
Some good finnish metal bands that i've listened: Amoral(newest album is lol, our Idol winner joined it after its current solist broke up with band,so i only recommend first 3 albums)Kalmah, Eternal tears of sorrow, Ensiferum(folk metal), Moonsorrow(death/folk metal),Mors principium est, Noumena, Stam1na(might not be everyone's thing since they sing in finnish, very strapping young lad-like), Wintersun(melodic metal/folk/black)
There.
Edit: blah, too lazy to add youtube links to all bands :p