Screaming Females, without a doubt. Their style has always been straight up drums and guitar rock, but they've covered the full gamut within that genre. You'll find pure punk, 90s skater screamo, power metal, pop ballads, like, everything, BUT that's not the impressive part; the impressive part is that within every genre, every single song ROCKS. Every song gets my foot tapping and my head bobbing, and that's a fucking feat. Marissa Paternoster is one of the best song writers in the US today, and the fact that they haven't received anywhere near the popular acclaim that they deserve is a dire testament to the impending downfall of this country.
They fuckin rock.