Emo, Screamo, and Papa Roach are not Metal to begin with, and the groups you listed are fairly generic.
Unexpect is one metal band that sits high atop a throne of uniqueness, if you can find it, buy In A Flesh Aquarium, easily one of the most eccentric and original albums I've listened to.
Otherwise, here are a few of my favorite Metal groups;
Pain of Salvation, Dream Theater, Ayreon, Riverside, Epica, Wintersun, Kamelot, Opeth, Ensiferum, Diablo Swing Orchestra, Symphony X, Therion, and Haggard.
The Gathering and Porcupine Tree are two of my favorite groups, that I only mention because they both have some Metal material strewn about their discography, though The Gathering and Porcupine Tree are ordinarilly Trip Rock and Progressive Rock, respectively.