I've been on a huge Anthrax kick lately. I've liked them since Jr High (mid/late '80s), but I was far more into Metallica, Slayer and Testament at the time. I'd play an Anthrax tape every now and again, but it was more to change things up than anything else.
Picked up Worship Music a while back, but didn't get to really listen to it until about 3 months ago. It's by far the best album I've heard in years. Just a kick-ass old school yet new sounding at the same time thrash album. If you haven't heard it, you've got to pick it up. People get all worked up about who's fronting them, and there's some interesting and well deserved controversy about Belladonna's return on this one. If you can't put someone else's drama aside and just listen to an album for what it is, you'll miss out on what I think is an awesome album.
Worship Music got me to buy some of their old stuff, as I wanted to refresh my memory with stuff beyond the one greatest hits album I had (Return of the Killer A's). Bought Among the Living, State of Euphoria, and Persistance of Time. Wondering why I didn't pay far more attention to these guys. Just such a kick-ass band. Can't turn them off.
Rage Against The Machine has been on heavy rotation too. Different than just about everything that's been mentioned here, but metal nonetheless (IMO of course).