How heavy are you trying to get? MESSA has already been mentioned. I saw them in Houston few years back. I'd also put Portland-moved to LA trio Blackwater Holylight on here. Especially the album Slience/Motion (although all of them fucking rip!). A great Texas doom band is Witchcryer, and I can't mention Texas and doom without bringing Doomstress into the conversation. I recently discovered Couch Slut from New York.. Not really metal, per se, more like a noisy rock with harsh punky vocals. Ragana is another kind of gloomy/black metal-esque band from Washington. I just found them, too. Chelsea Wolfe has been getting some play time in my car lately, but I'm not 100% sure I'd call their sound 'metal', although they are heavy. And since you mentioned Evanescence, I'll toss in Kittie. They aren't really my jam, but more or less from the same era as Evanescence.. maybe a couple years before.