Meshuggah, because I like polyrhythms.
Opeth, because I like their overall sound.
Morbid Angel, because of their blastbeats and strangeness.
Dream Theater, because of their complexity.
Just recently, Ulver, because of their stylistic change which they still manage to sound good in.
That's all I can think of for now. I'll edit the post and add more later if I remember anything.
EDIT: (of course)
Emperor, especially their earlier albums, because of the atmosphere.
Cryptopsy, because of the drummer and complexity of the music.
King Diamond, because of the melodics and for King Diamond's silly falsetto voice.
Behemoth, because of their ridiculous heaviness in their later albums.
Dan Swanö, because he is Dan Swanö.
Lastly, Green Carnation, and only because I also want to make a massive 60-minute song.