What is the best pedal for a more distorted/alternative/metal tone?

I play an American Standard Strat, and have a Fender Blues Junior. Love Love Love the tone I get from both. I also have "the dream pedal" The Ibanez Tube Screamer. Which thanks to former posts recommended, I purchased and I freakin love!!!!!!!! BUT, I also need one more pedal for a little "harder" distorted Alternative/Metal sound. I also have a little Line 6 practice amp that has the Insane and Metal ons, which is great, but I want to add that tone (or similar) to my blues Junior. And I'm not going to go out and buy 5 pedals, I'm more of a 1 pedal at a time guy, focusing primarily on TONE!!! Ya get to many pedals you lose the beautiful tone of your expensive guitar. Any suggestions would be helpful. Thank you