My Boss OD-3 does the job at the moment. I must say, I'm not a particular nut when it comes to the respective quality of stompboxes, I just paly around with whatever I've got until I get something I can use. Sure I might not get the perfect tone, but at least I'll sound a bit different. I'm a bit hesitant about getting a tube-screamer, simply because it seems that everyone who plays the sort of styles I like uses one, and I'm not a big fan of "standard" tones.